The fraction of Sr-90 left after 88 years is 0.1726
Initial mass of the isotope = N₀
Time taken by the sample, t = t(1/2)
Formula used :
N = N₀ * e^(-λt)
λ = 0.693 / t (1/2)
where,
N₀ = initial mass of isotope
N = mass of the parent isotope left after the time, (t)
t(1/2) = half life of the isotope
λ = rate constant
We have:
t = (2033 - 1945 )years = 88 years
So, on substituting the values:
N = x * e^(0.693*88years/28.8years)
Now put all the given values in this formula, we get the fraction of Sr-90 as
N = N₀ * e^-1.7566
N = N₀ * 0.1726
N/N₀ = 0.1726
The fraction of Sr-90 left after 88 years = 0.1726.
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how many grams are 2.9 moles of x1y4z6 where x has an atomic mass of 189.5 y has an atomic mass of 197.6 z has an atomic mass of 115.7
The mass of 2.9 mol of the given compound is 4854.89 g.
What is a mole?A mole can be specified as a standard unit that is used to determine a given count of particles. A mole can be used to evaluate a huge number of quantities of atoms, or molecules.
Given, the atomic mass of the X = 189.5
The atomic mass of Y = 197.6
The atomic mass of Z = 115.7
The molecular formula of the compound is X₁Y₄Z₆.
The mass of one mole or molar mass = 189.5 + 4 (197.6) + 6(115.7) = 1674
Given, the number of moles of X₁Y₄Z₆ = 2.9 mol
The mass of 2.9 moles of X₁Y₄Z₆ = 2.9 × 1674 = 4854.89 g
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The compound between Sulfur and Magnesium is _
Answer:
Magnesium sulfide
Explanation:
Determine whether each of the examples represents a colligative property or non colligative property
1. freezing point depression
2. density
3. boiling point elevation
4. vapor pressure lowering
5. colour
a. colligative
b. non colligative
c. colligative
d. colligative
e. non colligative
Colligative qualities include boiling point elevation, freezing point depression, and vapor pressure reduction. Color and density are non-colligative qualities.
Colligative qualities are those that rely on the number of particles of solute rather than the composition of the solute.
An example of a colligative property:
Reduced vapor pressure
Boiling point at an elevation
a drop in the freezing point
The osmotic pressure
Non-colligative qualities are those that are determined by the nature of the solute and solvent.
Non-colligative qualities include:
Viscosity
The surface tension
Density
Solubility
As a result, we may deduce that boiling point elevation, freezing point depression, and vapor pressure reduction are all colligative qualities. Color and density are also non-colligative qualities.
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A student wants to determine the effect of a fertilizer on the growth of bean plants. She sets
up the following experiment.
Bean
Soil
Fertilizer
Daily water 50 mL
A
Bean
Soil
Daily water 50 mL
2. What does setup "B" represent and why is it important in this experiment?
ANSWER QUESTION 2 NOT QUESTION 1
The experimental set up in B is to observe the growth the green beans without the addition of fertilizer. Thus, we can compare the growth of the plant with and without fertilizer and thereby we can understand the effect the fertilizer on the plant growth.
What is fertilizer?Fertilizers are chemical substances used to nourish the plants by making the soil rich in nutrients and minerals. Plants needs minerals along with water such as potassium, calcium, phosphorous, nitrogen etc.
Sometimes the soil comes deficient of these minerals and we have to fertilize the soli by the addition of the chemicals containing these minerals. Hence, fertilizers provide a nutrient rich soil for plant growth.
The experimental set up with fertilizer added plant and the second one (B) without fertilizer helps to compare the growth in both conditions and we can clearly understand how fertilizers effect the growth of plants by comparing the plant growth in A and B.
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for the reduction of benzophenone into diphenylmethanol, how would the rf values of reactant vs. product compare?
The Rf of diphenylmethanol (product) is smaller than that of the benzophenone(reactant) .
What is benzophenone used in?
In addition to being a flavoring agent, fragrance enhancer, perfume fixative, and additive for plastics, coatings, and adhesive formulations, benzophenone is also utilized as a UV curing agent. In order to protect cosmetics from harm from ultraviolet light, benzophenone is also used as a screen.
What are the side effects of benzophenone?
Both photocontact dermatitis and the raditional allergic contact dermatitis are caused by benzophenone sensitivity. Products containing benzophenone or benzophenone derivatives may produce redness, swelling, itching, and fluid-filled blisters in people who are allergic to benzophenone.
What is Diphenylmethanol used in?
Diphenylmethanol (DPM) and its derivatives are crucial components in the production of cosmetics, drugs, and practical organic compounds.
How do you make Diphenylmethanol?
A Grignard reaction involving phenylmagnesium bromide and benzaldehyde can produce diphenylmethanol. The reduction of benzophenone using sodium borohydride, zinc dust, or sodium amalgam and water is an alternate approach.
As, we know that,
Diphenylmethanol is an alcohol and benzophenone is a ketone.In Diphenylmethanol there is dipole-dipole interactions and hydrogen-bonding.In benzophenone there is dipole-dipole interaction.Here, Product is more polar than the reactant.Also, Diphenylmethanol has a higher affinity.To know more about
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• How does the weight on a bicycle affects the force required to affect its motion?
Answer:
More mass means more force is needed to achieve the same change in speed in the same amount of time. That force is transmitted from the road, to the tires, to the wheels, through the brakes, to the frame and rider.
The weight on a bicycle affects the force required to accelerate it as it increases inertia it will slow down its rate of acceleration.
What is Acceleration?
Acceleration is defined as the rate of change of velocity of an object with respect to time. These are vector quantities which have magnitude as well as direction.
The orientation of the acceleration of an object as given by the orientation of the net force acting on that object. It is expressed as:
[tex]\overline{a} = \frac{v - v_0}{t} = \frac{\Delta v}{\Delta t}\overline{a} = average acceleration\\v = final velocity\\v_0 = starting velocity\\t = elapsed time[/tex]
Acceleration is proportional to the force applied, so the greater the force, the greater the speed of the object in the direction of the force. Mass is inertia, which is the reluctance to accelerate, so for the same force, more massive objects experience smaller acceleration than less massive objects.
Thus, the weight on a bicycle affects the force required to accelerate it as it increases inertia it will slow down its rate of acceleration.
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a tank at is filled with of sulfur hexafluoride gas and of dinitrogen difluoride gas. you can assume both gases behave as ideal gases under these conditions. calculate the mole fraction and partial pressure of each gas, and the total pressure in the tank. be sure your answers have the correct number of significant digits. sulfur hexafluoride mole fraction: partial pressure: dinitrogen difluoride mole fraction: partial pressure: total pressure in tank:
The mole fraction of sulfur hexafluoride gas X(SF₆) = 0.361 and the mole fraction of dinitrogen difluoride gas X(N₂O) = 0.639
moles of each gas
n = m / M
where,
n: moles and m: mass, M: molar mass
SF₆: 16.7 g / 146.06 g/mol = 0.114 mol
N₂O: 8.88 g / 44.01 g/mol = 0.202 mol
The total number of moles is 0.114 mol + 0.202 mol = 0.316 mol
To calculate the mole fraction of each gas
X = moles of gas / total number of moles
X(SF₆) = 0.114 mol / 0.316 mol = 0.361
X(N₂O) = 0.202 mol / 0.316 mol = 0.639
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For 55.0seconds, Trevor was hang gliding at a constant velocity. In that time, he moved 583 meters to the southeast, and a flock of Canada geese flew past him at 17 meters per second. What was Trevor's velocity?
The velocity of Trevor, given that for 55.0 seconds, he moved 583 meters sountheast is 10.6 m/s
How do I determine the velocity of Trevor?Velocity is simply defined as the rate of change of displacement with time. Mathemathically, it is given as:
Velocity = displacement / time
With the above formula, we can obtain the velocity of Trevor as illustrated below::
Time = 55.0 secondsDisplacement = 583 meters southeastVelocity of Trevor =?Velocity = displacement / time
Velocity = 583 meters / 55.0 seconds
Velocity = 10.6 m/s
Thus, from the calculation made above, we can conclude that the velocity of Trevor is 10.6 m/s
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An atom has 8 protons, 8 neutrons, and 10 electrons.
What is the mass of this atom?
16 is the mass of this atom.
The Oxygen (O) has an atomic number of 8 and has a mass number of 16. Upon accepting 2 electrons it becomes O2-. The mass number is defined as the sum of the number of protons and neutrons present in the molecule. So here for O2- it contains 8 protons,8 neutrons and 10 electrons.
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After hockey practice, Carissa and Keenan were playing a game where they were pushing some objects to get them to crash. They were using a cone and two different pucks—a black one with more mass for Crash 1 and a blue one with less mass for Crash 2. They want to know what happened to the cone. Use the information from the diagram to answer. In which crash did the cone experience a stronger force? How do you know?
The crash where the cone experience a stronger force is option D because: Crash 1: the force on the black hockey puck was stronger in this crash, so the force on the cone was also stronger.
Does it take a stronger force to slow something down?The ball is drawn back to Earth by gravitational force. The ball returns to Earth as a result of friction. The ball is forced back toward Earth by magnetic force.
A puck's velocity changes when a player makes contact with it when it is still. He causes the puck to speed up, in other terms. The hockey stick's force, which causes the acceleration, is responsible. The velocity grows as long as this force is in motion.
Therefore, the force applied to an object must be larger than what is required for a progressive slowing down if the object must be slowed down quickly. For instance, a bicycle's brakes will slow or stop it more quickly the more force is given to it.
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See full question below
After hockey practice, Carissa and Keenan were playing a game where they were pushing some objects to get them to crash. They were using a cone and two different pucks—a black one with more mass for Crash 1 and a blue one with less mass for Crash 2. They want to know what happened to the cone.
Use the information from the diagram to answer.
In which crash did the cone experience a stronger force? How do you know?
answer choices
There was no force on the cone. In both crashes, only the hockey puck experienced a force.
The diagram doesn’t tell you anything about the force on the cone. It only gives information about the force on the pucks.
It was the same force in both crashes; the hockey puck changed speed by the same amount in each crash, so the force on the cone was the same each time.
Crash 1; the force on the black hockey puck was stronger in this crash, so the force on the cone was also stronger.
3 The density of wood is 0.5g/cm³. What is its value in S1 unit?
The value of the density of wood that is 0.5g/cm³ in SI units would be 500 [tex]kg/m^3[/tex].
What is an SI unit?The SI unit is an acronym for the international system of units. It is a system that guides measurements generally in science. It consists of 7 base units:
Time in secondsLength in metersMass in kilogramsElectric current in amperesTemperature in KelvinAmount of substance in moleLuminosity in candelaThus, for a density that is in g/cm³, the SI unit should be kg/m3.
0.5 g/cm³ = 0.5g/1 cm³
1 g = 0.0001 kg
0.5 g = 0.5/1000 = 0.0005 kg
1 cm³ = 1 x [tex]10^{-6[/tex] [tex]m^3[/tex]
Thus, 0.5 g/cm³ = 0.0005 kg/1 x [tex]10^{-6[/tex] [tex]m^3[/tex]
= 500 kg/m^3.
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a 1.50 g sample of hydrocarbon undergoes complete combustion to produce 4.40 g of co2 and 2.70 g of h2o. what is the empirical formula of this compound? in addition, its molecular weight has been determined to be about 78. what is the molecular formula?
the empirical composition of this substance Its molecular weight has also been calculated to be around 156.
the molecular equation Response: CGHG.
Calculate the grams of carbon and hydrogen in 4.40 g of CO2 and 2.70 g of H2O, respectively.
4.40 g x (12.011 g/44.0098 g) = 1.20083 g of carbon
2.70 g times (2.0158 g / 18.0152 g) Equals 0.3021482 g of hydrogen
2) Calculate the corresponding number of moles from the grams of C and H molecular weight..
20083 g / 12.011 g/mol = 0.09998 mol of carbon
In terms of hydrogen, 0.3021482 g / 1.0079 g/mol equals 0.2998 mol
3) To break up the molar amounts listed above into smaller, more manageable amounts, divide each one by its lowest value.
numbers.
0.09998 mol/0.09998 mol = 1 for carbon.
hydrogen: 0.298 mol/0.0998 mol = 2.9986 mol = 3
We have now discovered the solution: the substance's empirical formula is CGHG
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calculate the concentrations of all species present in a 0.29 m solution of ethylammonium chloride (c2h5nh3cl).
The concentrations of all species present in a 0.29 m solution of ethylammonium chloride is 0.00000223
pKa for C2H5NH3+ = 10.7
pKw = 14.0
pKa + pKb = pKw
10.7 + pKb = 14.0
pKb = 14.0 - 10.7
pKb = 3.30
C2H5NH3Cl is a salt of ethylamine and HCl so it will dissolve in water to produce C2H5NH3^+ + Cl^-
The base hydrolysis reaction: C2H5NH3^+(aq) + H2O(l) <=> C2H5NH2(aq) + H3O^+(aq)
This reaction is described by Kb.
Kb = [C2H5NH2][H3O^+]/[C2H5NH3^+]
Let [C2H5NH2] = [H3O^+] = x,
so [C2H5NH3^+] = 0.29 - x
Kb = x^2/(0.29 - x) = 2.00 x 10^-11
Let's solve for x. In this equation, It is possible to solve without the use quadratic equation. So we can assume that 0.29 - x is approximately equal to 0.29. We won't know until we do the calculation.
We get: x^2 + 2.00 x 10^-11x - 4.99 x 10^-12 = 0
With the use of a quadratic calculator.
x = 2.23 x 10^-6 M = [C2H5NH2] = [H3O^+]
0.29- x is just 0.26 M in this problem because 2.23 x 10^-6 M is insignificant.
[C2H5NH3^+] = 0.29 M = [Cl^-]
NOTE:
pH = -log [H3O^+] = -log(2.23 x 10^-6) = 5.65
Ka is the acid dissociation constant
Kb is the base dissociation constant
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an ideal gas is brought through an isothermal compression process. the 5.00 mol of gas goes from an initial volume of 224.2 cm3 to 104.3 cm3 . if 1842 cal is released by the gas during this process, what is the temperature of the gas? [1 cal
an ideal gas is brought through an isothermal compression process. If 1842 J is released by the gas during this process, the temperature of the gas is 134.27 K
Isothermal compression is the thermodynamic method of decreasing volume or increasing pressure when the system temperature remains constant. Thermal equilibrium is maintained throughout the process.
When a gas is compressed isothermally, work is carried out on the system to reduce volume and increase pressure. Working on the gas increases its internal energy and tends to raise its temperature. To keep the temperature constant, energy must escape the system as heat and enter the environment.
According to the question, this is the case of isothermal reversible compression of gas.
As per the first law of thermodynamics,
where,
ΔU = internal energy
q = heat
w = work done
As we know, the term internal energy depends on the temperature and the process is isothermal which means at a constant temperature.
Thus, at a constant temperature, the internal energy is equal to zero.
q = -w
Thus, w = -q = 1842 J
The expression used for work done will be,
W = nRT ln(Vf/Vi)
where,
w = work done = - 1842 J
n = number of moles of gas = 5 mole
R = gas constant = 8.314 J/mole K
T = temperature of gas = ?
Vi = initial volume of gas
Vf = final volume of gas
Now put all the given values in the above formula, and we get the temperature of the gas.
- 1842J = 5 mole * 8.314J/mole K*T*ln (104.3 * 10−6 m3/224.2 * 10−6 m3)
T = 134.27
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you run a reaction which will make ammonia (nh3) as a product. you predict that you should make 8.41 x 1024 molecules of ammonia in your reaction. how many grams of ammonia will you make if your prediction is correct?
The molecules of ammonia in your reaction. the grams of ammonia will you make is 2.39 g.
given that :
the no. of molecules of the ammonia : 8.41 × 10²⁴
molar mass of ammonia : 17 g /mol
no. of molecules = (mass / molar mass ) × Avogadro's number
8.41 × 10²⁴ = (mass / 17 ) × 6.022 × 10²³
mass = 17 / 7.1
mass = 2.39 g
Thus, a reaction which will make ammonia as a product. you predict that you should make 8.41 × 10²⁴ molecules of ammonia in your reaction. grams of ammonia will you make is 2.39 g.
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compare the temperature changes in the stratosphere with those in the thermosphere. Include the role of ozone in your explanation
The stratosphere, which can be found above the troposphere and below the mesosphere, is the second layer of the Earth's atmosphere (/straetsfr, -to-).
What is stratosphere?The stratosphere is an atmospheric layer that is made up of stratified temperature levels, with the warm layers of air high in the sky and the cool layers of air low in the sky, near the surface of the Earth. The ozone layer's ability to block the sun's ultraviolet (UV) radiation is what causes temperatures to rise with altitude. As opposed to the troposphere, which is close to the Earth's surface, where temperature drops with height, the temperature inversion is a phenomenon.The tropopause border, which separates the temperature inversion from the troposphere, is located between the two layers of the atmosphere.The lower stratosphere can reach heights of 20 km (66,000 ft; 12 mi) close to the equator, 10 km (33,000 ft; 6.2 km) in midlatitudes, and roughly 7 km at the poles (23,000 ft; 4.3 mi). Temperatures range from a mean of 51 °C (60 °F; 220 K) near the tropopause to a mean of 15 °C (5.0 °F; 260 K) towards the mesosphere. The stratosphere's temperatures also alter with the seasons, dropping to especially low levels during the polar night (winter). In the Southern polar vortex, stratospheric winds can reach speeds of up to 60 m/s (220 km/h; 130 mph), significantly exceeding those in the troposphere.To Learn more About stratosphere, refer To:
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✔ Question 1
Below is a picture of the rock strata of a mountain.
What can you infer about the layers in this picture?
Sedimentary rock layers are referred to as rock strata.
What is a rock?A rock is a dense mass of mineral grains that have grown or been cemented together over time. There are big rocks and little rocks. Pebbles are little rocks.
The sediment grains that are deposited by water, wind, or ice become sedimentary rocks. They are always formed in layers and are referred to as "beds" or "strata," and frequently include fossils.
Weathering, erosion, deposition, compaction, and cementation are the processes that result in the formation of these horizontal layers. Newer layers are deposited and created during this process on top of older layers, allowing for the relative dating of each layer.
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what special equipment did niels bohr use to develop his atomic model?
Neil Bohr used the fluorescent screen and an alpha particle detector to study the structure of an atom.
What is an atom?
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
The atom as a whole is neutral and stable due to presence of oppositely charged particles.
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How is melting similar to freezing? How is it different?
Melting and freezing refer to the changes in state which occur when the solid and liquid states interchange. Melting occurs when a solid is heated and turns to a liquid and freezing occurs when a liquid is cooled and turns to a solid.
Answer:
Melting and freezing both require energy, however melting involves the speeding up of molecules, and freezing involves slowing them down
Explanation:
Which of the following is an example of a heterogeneous mixture?
salad
milk
paint
toothpaste
Answer:
salad
Explanation:
PLEASE HELP IM GONNA FAIL THIS WHOLE YEAR PLEASE
Answer:
Mg+HCl = MgCl+H2
Explanation:
you just have to write the correct formula of these elemernt
a 2.00g sample of limestone was dissolved in hydrochloric acid and all the calcium present in the sample was converted to ca2 (aq). excess ammonium oxalate solution, (nh4)2c2o4(aq), was added to the solution to precipitate the calcium ions as calcium oxalate, cac2o4(s). the precipitate was filtered, dried and weighed to a constant mass of 2.43g. determine the percentage by mass of calcium in the limestone sample.
In order to precipitate the calcium ions as calcium oxalate, a 2.00g sample of limestone was first dissolved in hydrochloric acid until all of the calcium was transformed to Ca²⁺ (aq). This was followed by the addition of excess ammonium oxalate solution, (NH₄)₂C₂O₄(aq). Filtered, dried, and weighed to a consistent mass of 2.43g. The percentage by mass of calcium in the limestone sample is 31.25%
The percentage by mass of calcium in the limestone can be calculate as follows:
Mass of precipitate that is calcium oxalate = 2.43 g
Moles of calcium oxalate = 2.00g /128 g/mol = 0.015625 moles
One mole of calcium atoms make up one mole of calcium oxalate.
so, 0.015625 moles calcium oxalate equal to 0.015625 moles calcium atoms
Mass of 0.015625 moles of calcium :
0.015625 mol × 40 g/mol = 0.625 g
Mass of sample of limestone = 2 g
Percentage of calcium in limestone:
(0.625 g/2 g) x 100 = 31.25%
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For a laboratory exercise in class, a student is given a mixture of small pieces of iron, sand, water, and salt. what physical property could be used to best separate the iron from the other ingredients?
a. Solubility
b. Magnetism
c. Melting Point
d. Electrical Conductivity
Answer:
solubility
Explanation:
the solid substances will be added to water to see which one is soluble
How many moles of chlorine are present in 3 moles of MgCl2
The amount, in moles, of chlorine that would be present in 3 moles of [tex]MgCl_2[/tex] would be 6 moles.
Stoichiometric problem[tex]MgCl_2[/tex] is made from magnesium and chlorine molecules according to the following equation:
[tex]MgCl_2 --- > Mg^{2+} + 2Cl^-[/tex]
From the above equation, 1 mole of [tex]MgCl_2[/tex] is made up of 1 mole of Mg and 2 moles of Cl.
Following this established ratio, the amount of chlorine that would be present in 3 moles of [tex]MgCl_2[/tex] can be calculated as follows:
1 mole [tex]MgCl_2[/tex] = 2 moles of Cl
3 moles [tex]MgCl_2[/tex] = 2 x 3/1
= 6 moles of Cl
In other words, 6 moles of Cl would be present in 3 moles of [tex]MgCl_2[/tex].
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please help!
Are magnesium and calcium more reactive with oxygen in the air than is aluminum? Support your answer.
Magnesium and calcium are 2nd group elements with 2 valence electrons. They are metals in room temperature and easily lose these electrons to nonmetals such as oxygen.
What is magnesium ?Magnesium is 12th element in periodic table. It is 2nd group element and is a called alkaline earth metals. Its group members are calcium, strontium, and barium.
They contains 2 valence electrons which can be easily lost to a non-metal. Oxygen is highly electronegative element and it contains 6 valence electrons and need two more electrons to achieve octet.
Al is 13th group element it is not as much electropositive as alkaline earth metals. It contains 3 valence electrons and thus it need to lose all these 3 electrons to achieve octet. Hence, Al is less reactive towards O2 in comparison with Mg and Ca.
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ANSWER ASAP FOR 90 POINTS Question: Air pressure is...
A.high and low at the bottom
B. same at the top same at the bottom
C.low at the top low at the bottom
D.low at the top hight at the bottom
Air pressure is D.low at the top hight at the bottom.
How much air pressure is typical?Pressure is the force that the air applies to the ground when gravity acts on it. At sea level, there is typically a pressure of 1013.25 millibars, or 14.7 pounds per square inch.
When the air pressure is high, what happens?High pressure frequently heralds sunny, dry weather. Clouds and precipitation are frequently indicative of low pressure. Air that is sinking is related with high pressure. Because it is pushing DOWN on the ground, air pressure is higher.
How do we react to air pressure?High barometric pressure exerts additional pressure against our bodies, which restricts how much tissue can expand. On the other hand, when air pressure is low, our body's tissues can expand more, which results in more pressure.
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a chemist reacted 0.20 moles 4-aminophenol (109.13 g/mol) with 0.25 moles of acetic anhydride (102.09 g/mol) to synthesize acetaminophen. if 22 g acetaminophen (151.163 g/mol) was generated, what was the percent yield of the reaction? (only type the number, not the percent sign)
If 22 g acetaminophen (151.163 g/mol) was generated. The percent yield of the reaction is 72.78 %.
Calculation :
C₆H₇NO + C₄H₆O₃ --> C₃H₉NO₂ + C₂H₄O₂
0.20 moles 0.25 moles 22g
limiting reagrnt --> C₆H₇NO
from reaction equation
.20 mol of acetaminophen = .20*151.163 = 30.23 g
% yield = (practical/ theoritical)yield* 100 = 72.78 %
reaction yield. The reaction yield (absolute yield) of a chemical reaction is the amount of pure, dry product recovered from the reaction. Relative yield or percent yield (%) is commonly calculated to measure the efficiency of chemical reactions in organic synthesis.
Yield, also called reaction yield, is a measure of the molar amount of product to reactant consumed in a chemical reaction, usually expressed as a percentage. Yield is one of the main factors that scientists must consider in organic and inorganic chemical synthesis processes. [2] In chemical reaction engineering, “yield,” “conversion,” and “selectivity” relate to unwanted products, how much of the starting material is consumed (conversion), how much of the desired production A term used to describe the rate at which something is formed (yield). (selectivity) represented as X, Y, and S
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The rate of effusion of substance A is 3 times the rate of effusion of substance B. If the molar mass of substance A is 4.00 g/mol, what is the molar mass of substance B?
The rate of effusion of substance A is 3 times the rate of effusion of substance B, and molar mass of A is 4g/mol, then molar mass of B is 36g/mol.
Graham Law:
The rate of effusion of a gaseous substance is inversely proportional to the square root of its molar mass. This is called Graham's Law
R = k/√M
where k is constant and m is molar mass of the substance.
rate of effusion of substance A is 3 times the rate of effusion of substance B.
molar mass of substance A is 4.00g/mol
Ra = 3Rb
Ra/Rb = √Mb/√Ma
3Rb/Rb = √Mb/√4
3 = √Mb/2
√Mb = 6
Mb = 36
so, molar mass of substance B is 36g/mol.
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Describe early models of the atom in less than 75 words. Start with Democritis, mention the contributions of Aristotle, John Dalton, Rutherford, Thomson, and Bohr.
Democritus said matter can not be divided indefinitely, Aristotle said that matter was made of four elements while John Dalton proposed a modern atomic model based on experimentation. Rutherford said atoms are mostly empty space, Thompson brought about negative electrons in a positive framework. Bohr said that electrons orbit the nucleus in “shells.
What are the atomic models?There are many atomic models that was proposed which includes:
the Bohr model, the Rutherford model, the probability model, the orbital model, the probability orbit model, and the wave model.Rutherford in his experiment shot alpha (α) particles at gold foil whereby most particles passed through.
Hence he concluded the following:
atoms are mostly empty. a “nucleus” is positive and holds most of an atom’s massSome positive α-particles deflected or bounced back.
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how are windbelts formed Please answer ASP its 30 points!!
Answer:due to unequal heating
Explanation:
