Heat flows from hotter objects to colder objects until it reaches a state where heat is no longer flowing.What have the objects reached when heat is not longer flowing?
the ideal of stationary orbit was first given by?
Answer:
Neil Bohr
Explanation:
Thank me latur✊
The half-life of 226Ra is 1.60x103 years. How long until only 12.5% of the original sample of 226Ra remains?
Answer:
4.80×10³ years
Explanation:
Let the original amount (N₀) of ²²⁶Rn = 1 g
Therefore,
12.5% of the original amount = 12.5% × 1 = 12.5/100 × 1 = 0.125 g
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Original amount (N₀) = 1
Amount remaining (N) = 0.125 g
Number of half-lives (n) =?
N = 1/2ⁿ × N₀
0.125 = 1/2ⁿ × 1
0.125 = 1/2ⁿ
Cross multiply
0.125 × 2ⁿ = 1
Divide both side by 0.125
2ⁿ = 1/0.125
2ⁿ = 8
Express 8 in index form with 2 as the base
2ⁿ = 2³
n = 3
Thus, 3 half-lives has elapsed.
Finally, we shall determine the time taken for only 12.5% of the original sample of ²²⁶Rn to remain.
This can be obtained as follow:
Half-life (t½) = 1.60×10³ years
Number of half-lives (n) = 3
Time (t) =?
t = n × t½
t = 3 × 1.60×10³
t = 4.80×10³ years.
Thus, it will take 4.80×10³ years for 12.5% of the original sample of ²²⁶Rn to remain.
when are igneous rocks formed?
A. When layers of mud form inside Earth
B. When layers of mud are compressed
C. When melted rock solidifies
D. When solid rock melts
Answer:
C. When melted rock solidifies.
PLEASE HELP!!
A scientist places a pH meter in a sample of concentrated potassium hydroxide (KOH). The scientist slowly adds nitric acid (HNO3) to the KOH and monitors the pH. Describe how the pH and hydronium ion concentration will change in the solution as the acid is added.
Answer:
pH of the solution will decrease & hydronium ion concentration will increase in the solution as the acid is added.
Explanation:
Using the periodic table, choose the more reactive nonmetal.
Te or O
Answer:
answer is TE
Explanation:
Answer:
Tellurium is more reactive than Oxygen
What is thePercent composition of dichlorine heptoxide?
Answer:
The percent composition of dichlorine heptoxide is 38.76% CI and 61.24% O
Answer:
38.76%cl and 61.24%o
Explanation:
the percent composition of dichlorine heptoxide is 38.76%Cl and 61.24%O
Rank the following compounds in order of increasing solubility in water. Items (4 items) (Drag and drop into the appropriate area) No more items Items in order most soluble CaO BaO KCI KI
I have tried CaO> BaO > KCl > KI, this is incorrect.
Answer:
CaO < BaO < KCl <KI
Explanation:
Let us remember that the solubility of an ionic substance in water depends on the magnitude of the lattice energy and the hydration energy. If the hydration energy is equal to or is greater than the lattice energy, the substance dissolves in water.
However, the lattice energy depends on the size of the ions. The smaller the ions in the ionic compound, the higher the lattice energy and the lesser the solubility of the ionic compound.
KI has the least lattice energy and the highest solubility in water while CaO has the highest lattice energy and the least solubility in water.
1. Chlorofluorocarbons (CFCs) are of interest because of their ability to destroy ozone molecules. A carbon-chlorine bon din the CFC molecule can be broken by sunlight, leaving a highly reactive free radical which then goes on to destroy the surrounding ozone molecules. The energy of a C-Cl bond is 328 kJ/mole. Calculate the wavelength of light needed to break a bond in a single molecule. In which region of the spectrum (infrared, visible, UV) does this wavelength fall
Answer:
See explanation
Explanation:
Energy of the photon (E) = 328 * 10^3/6.02 * 10^23 = 5.45 * 10^-19 J
Recall that E = hc/λ
h = Plank's constant = 6.36 * 10^-34 Js
c = speed of light = 3 * 10^8 m/s
λ = ??
λ = hc/E
λ = 6.36 * 10^-34 * 3 * 10^8/5.45 * 10^-19
λ = 3.5 * 10^-7 m
This falls into the UV region of the spectrum
PLEASE PLEAS HELP I REALLY NEED IT
Answer:
A i took the quiz
Explanation:
Consider the following equilibrium
N204(9) - 2NO2(9) Keq = 5.85 x 10-3
Which statement about this system is true?
If the equilibrium concentration of NO2 is 1.78 x 10-2 M, the equilibrium concentration of N2O4 is
The equilibrium concentration of N₂O₄, given that the concentration of NO₂ is 1.78×10⁻² is 5.42×10⁻²
Data obtained from the question N₂O₄ <=> 2NO₂Equilibrium constant (Keq) = 5.85×10⁻³ Equilibrium concentration of NO₂ = 1.78×10⁻²Equilibrium concentration of N₂O₄ =?How to determine the equilibrium concentration of N₂O₄Keq = [Product] / [Reactant]
Keq = [NO₂]² / [N₂O₄]
5.85×10⁻³ = [1.78×10⁻²]² / [N₂O₄]
Cross multiply
5.85×10⁻³ × [N₂O₄] = [1.78×10⁻²]²
Divide both sides by 5.85×10⁻³
[N₂O₄] = [1.78×10⁻²]² / 5.85×10⁻³
[N₂O₄] = 5.42×10⁻²
Learn more about equilibrium constant:
https://brainly.com/question/17960050
#SPJ1
Answer:
First answer is "The equilibrium lies to the left", and the second one is 5.42 x 10^-2 M.
Explanation:
Hope i helped yall :D
Give an example of an electrolyte
Answer: sodium chloride water solution
Explanation: Eelctrolyte contains cations and anions which can
Transfer charge
Answer:
some energy drinks like powerade or Gatorade, and some juice drinks to.
Balance C3H8 + O2 + CO2 + H2O
Assuming the second plus sign is a typo and was meant to be a reaction arrow, this would be the balanced equation:
C3H8 + 5O2 —> 3CO2 + 4H2O
HELP FAST 75 PTS Calculate the amount of heat needed to melt 35.0 g of ice at 0 ºC. must show work
Answer:
It takes 12,000 Joules of energy to melt 35 grams of ice at 0 °C
Explanation:
Good Luck!
what does pen mean?.
Answer:
P = protons
E = electrons
N = neutrons
remember protons and neutrons (protons are positive and neutrons are neutral as you can already tell by their names) are found at the centre of the nucleus (positive mass). Whilst the electrons (negative) orbit around the shells
Explain what method you would use to obtain
Petrol (boiling point 20
60 C) from a mature of petrol and kerosene (boiling point 180 220 C)
Answer:
Fractional distillation of crude oil in laboratory
Explanation:
In general, we can sort them according to their boiling point.
We should first place a ball of mineral wool soaked with petroleum into a boiling tube and heat it with a Bunsen flame. At the beginning of the experiment, heat the mineral with a gentle flame, and then more strongly later. The fraction with a lower boiling range will distil out first. Since petrol is quite volatile, it should be condensed by cooling with water or an ice-water bath.
Petrol will be collected first, as it has a lower boiling point than kerosene. It will turn into vapour and condense again in the receive tub in the beaker.
g You are given a 1.25 gram mixture of calcium nitrate and calcium chloride. You dissolve this mixture in 200.0 mL of water and add an excess of 0.300 M silver nitrate. You collect and dry the white precipitate which forms and find it has a mass of 0.535 grams. Calculate the percent calcium chloride by mass in the original mixture.
Answer:
16.51%
Explanation:
The reaction that takes place is
CaCl₂(aq) + 2AgNO₃(aq) → 2AgCl(s) + Ca(NO₃)₂(aq)Meaning that the white precipitate that formed is AgCl. Now we convert 0.535 g of AgCl into moles, using its molar mass:
0.535 g ÷ 143.43 g/mol = 0.00373 mol AgClThen we convert 0.00373 moles of AgCl into moles of CaCl₂, using the stoichiometric coefficients:
0.00373 mol AgCl * [tex]\frac{1molCaCl_2}{2molAgCl}[/tex] = 0.00186 mol CaCl₂We convert moles of CaCl₂ into grams, using its molar mass:
0.00186 mol CaCl₂ * 110.98 g/mol = 0.206 gFinally we calculate the percent of CaCl₂ by mass in the original mixture:
0.206 g / 1.25 g * 100% = 16.51%The percent calcium chloride by mass in the original mixture is 16.4%
The equation of the reaction between calcium nitrate and silver chloride is:
[tex]\mathbf{CaCl_2 + 2AgNO_3 \to 2 AgCl+Ca(NO_3)_2}[/tex]
Given that;
the weight mass of the white precipitate formed is = 0.535 gramsthe number of moles of the precipitated AgCl is:
= 0.535 g / 143.32 g/mol
= 0.0037 moles
From the above reaction, If 2 moles of AgCl are formed by 1 mole of CaCl2
Then, 0.0037 moles of AgCl will form (0.0037 × 1)/2 moles of CaCl2.
0.0037 moles of AgCl will form 0.00185 moles of CaCl2.
Now, we can say that the number of moles of CaCl2 present in the mixture is = 0.00185 moles
Mass amount of CaCl2 present = 0.00185 moles × 110.98 g/mol
Mass amount of CaCl2 present = 0.205 grams
Finally, the mass percentage [tex]\mathbf{=\dfrac{0.205}{1.25}\times 100\%}[/tex]
= 16.4%
Therefore, we can conclude that the percent calcium chloride by mass in the original mixture is 16.4%
Learn more about mass percentage here:
https://brainly.com/question/23991850?referrer=searchResults
Describe how chemical reactions are affected by reaction conditions
of monction?
Answer:
hope his helps
Explanation:
Mention the factors affecting the rate of reaction
There are four main factors that can affect the reaction rate of a chemical reaction:
Reactant concentration. Increasing the concentration of one or more reactants will often increase the rate of reaction. ...
Physical state of the reactants and surface area. ...
Temperature. ...
Presence of a catalyst.
Ca3(PO4)2 + 3H2SO4 3CaSO4 + 2H3PO4.
What mass of concentrated H2SO4 (98% by mass) must be used to react completely
with 100.00 g of calcium phosphate?
100g
H2SO4 = 3x98x100/310 = 94.84g
used mass of h2so4x100/all mass of H2so4 = 98%
yx100/98=94.84x100/98 = 96.81.
Check the attached photo for clear answer.
What is the use of calcium phosphate?It may be used to treat conditions caused by low calcium levels such as bone loss (osteoporosis), weak bones (osteomalacia/rickets), decreased activity of the parathyroid gland (hypoparathyroidism), and certain muscle diseases (latent tetany).
Is calcium phosphate good for health?About Calcium Phosphate Supplements
It aids in healthy bone development and is crucial from infancy to adulthood. But, calcium does more than build strong bones. It's also very important for healthy digestion. Calcium aids in bile acid metabolism, excretion of fatty acids, and healthy gut microbiota.
Learn more about calcium phosphate at
https://brainly.com/question/10835189
#SPJ2
An iron sulfide compound is analyzed, and found to contain 11.26 g iron and 9.70 g sulfur. Determine the molar ratio of sulfur to iron in this compound, and hence its chemical formula.
Answer:
Molar ratio = 1.5Chemical formula = Fe₂S₃Explanation:
First we convert the given masses of each element into moles, using their respective molar masses:
Fe ⇒ 11.26 g ÷ 55.845 g/mol = 0.202 mol FeS ⇒ 9.70 g ÷ 32.065 g/mol = 0.302 mol SNow we divide them in order to calculate the molar ratio of S to Fe:
0.302 / 0.202 = 1.5Meaning that for each 1 Fe mol, there's 1.5 S moles. We can write that as Fe₁S₁.₅
Finally we double those subscripts so that they become the lowest possible integers: Fe₂S₃.
Do all materials respond to heat in the same way? Give an example to support your answer.
Answer:
yes.
Explanation:
Energy transfer will continue until the objects are at the same temperature. There are 3 ways in which thermal energy can be transferred from one object/substance to another, or from a system to its surroundings: Conduction. Convection.
All materials do not respond to heat in the same way because every material is made up of different arrangements of atoms and different substances, and different substances respond differently when reacting with heat.
What is heat?Heat is a form of energy that is produced by the burning of something. It is thermal energy that increases the warmth of a body or an atmosphere.
As long as the objects are not at the same temperature, energy transfer will continue. Three methods exist for transferring thermal energy from one thing or thing to another, or from a system to its surroundings: Conduction. Convection.
Thus, because each material is made up of a unique combination of atoms and substances, and because each substance reacts to heat in a unique way, no two materials react to heat in the same way.
To learn more about heat, refer to the below link:
https://brainly.com/question/20980273
#SPJ2
What is the percent composition of hydrogen in glucose
Answer:
67%Explanation:
Thus the % composition of glucose by mass is carbon 40.0 % oxygen 53.3 % hydrogen 6.7 % in this way, the % composition by mass of any compound can be calculated provided that is formed is known.How to balance NaOH+CO2=Na2CO3+H2O by algebraic method?
Which is a saturated solution?
A）40g NH4Cl in 100g water at 50°C
B）2g SOz in 100g water at 10°C
C）52g KCl in 100g water at 80°C
D）120g KI in 100g water at 20°C
Answer:
C）52g KCl in 100g water at 80°C
Explanation:
A saturated solution is one that contains as much solute as it can dissolve in the presence of excess solute at that particular temperature.
A solutibility curve is a graph that shows the variability with temperature of the solubility of a solute in a given solvent. A solutibility curve can provide information of whether a solution formed frommthe solute and solvent are saturated or not at a given temperature.
From the solubility curve in the attachment below:
A) A saturated solution of NH₄Cl will contain about 52 g solute per 100 g sat 50 °C. Thus, a solution of 40 g NH₄Cl in 100 g water at 50 °C is an unsaturated solution.
B) A saturated solution of SO₂ at 10°C will contain about 70 g of solute in 100 g of water. Thus a solution of 2g SO₂ in 100g water at 10°C is an unsaturated solution.
C) A saturated solution of KCl at 80 °C will contain about 52 g of solute in 100 g of water. Thus, a solution of 52g KCl in 100g water at 80°C is a saturated solution.
D) A saturated solution of Kl at 20 °C will contain about 145 g of solute in 100 g of water. Thus, a solution of 120g KI in 100g water at 20°C is an unsaturated solution.
what are the twa parts of central nervous system ?
Answer:
The nervous system has two main parts: The central nervous system is made up of the brain and spinal cord.
Explanation:
how many grams of hcl would be produced if 54 grams of water were used
Answer:
i dont know
Explanation:
its simple i dont know
Answer:
Explanation:Red
During a hurricane, what effect can the ocean have on the beach?
A.
Only the wind from a hurricane affects the land.
B.
Only the rain from a hurricane affects the land.
C.
The ocean can wash away much of the beach in a short time.
D.
The ocean always cleans litter from the beach during a hurricane.
If energy cannot be created or destroyed, what happens to the kinetic and potential energy?
Answer:
According to the law of conservation of energy, energy cannot be created or destroyed, although it can be changed from one form to another. KE + PE = constant. ... As the car coasts down the hill, it moves faster and so it's kinetic energy increases and it's potential energy decreases. hope this helps
Explanation:
Answer:
They cannot be destroyed or created however,
Explanation:
it can only be transformed or transferred from one form to another.
HELP ASAP WHATS THE DEFINITION I NEED JT NKW
Answer:
1.Summer solstice 2.seasons 3. winter solstice 4. Equinox
Explanation:
I hope it helps!
Have a great day!
how many atoms are in 0.5 mole of aluminum
According to the Avogadro's number, there are 3.011×10²³ atoms in 0.5 mole of aluminium.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number, on substituting values in formula, 0.5×6.023×10²³=3.011×10²³ atoms.
Thus, there are 3.011×10²³ atoms in 0.5 mole of aluminium.
Learn more about Avogadro's number,here:
https://brainly.com/question/11907018
#SPJ2
