Answer:
Any element in group 1 has just one valence electron. Examples include hydrogen (H), lithium (Li), and sodium (Na). Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons).
Explanation:
How many valence electrons does each element have?
The Group 1 atoms have 1 valence electron. The Group 2 atoms have 2 valence electrons. The Group 3 atoms have 3 valence electrons. The Group 4 atoms have 4 valence electrons.
I hope it's helpful
Stomata
layer that
on the lower epidermal
move through
1
internal cells packed together to expose the
greatest number to
the
inside the
Chloroplast
where photosynthesis.occurs
PLEASE HELP!!!!
Answer:
dose it give you numbers
Explanation:
Stomata is present on the lower epidermal layer that helps gases to move through. The tissue between the upper and lower epidermis of leaves, called the mesophyll, is perfectly designed to carry out intensive photosynthesis.
What is stomata's function?Since this evolutionary development is so crucial to plant identity, almost all terrestrial plants use the same pores, known as stomata, to absorb carbon dioxide and release oxygen.
Stomata are microscopic openings that are crucial for photosynthesis. They swarm and are plentiful on the plants' surface.
The reason for this high concentration is that they have a lot of chloroplasts, which are the locations for photosynthesis.
Chloroplasts provide oxygen and create energy through photosynthesis to assist plant growth and crop output.
Thus, the mesophyll cells of the leaf contain many of chloroplasts. The tissue between the upper and lower epidermis of leaves, called the mesophyll, is perfectly designed to carry out intensive photosynthesis.
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What is the molar mass of magnesium sulfate, MgSO4?
Answer:
120.37 g/mol is the molar mass of magnesium sulfate
what element is this
Answer:
neon
Explanation:
there are 10 protons
Identify the products in the following chemical reaction: Multiply chose
2NaHCO3 + CaCl2 → CaCO3 + CO2 + 2NaCl + H2O
A. NaHCO3
B. CaCl2
C. CaCO3
D. CO2
E. NaCl
H2O
Answer:
C. CaCO3
D. CO2
E. NaCl
. H2O
When baking soda and vinegar react, the surface bubbles. What does this most likely indicate?
a chemical change, because a precipitate is being formed
a chemical change, because a gas is being formed
a non chemical change, because a precipitate is being formed
a non-chemical change, because a gas is being formed
Answer: B
a chemical change, because a gas is being formed
Explanation:
Answer:
B
Mark Brainliest please
Explanation:
The mass % of Ca in CaSO4 is 29.45%. To calculate the mass of Ca present in a 25.6-g sample of this compound, the correct procedure is given by _____.
Answer:
The correct answer is - 29.45 / 100 x 25.6 = 7.5392 grams
Explanation:
It is given in the question that in 100 gms of CaSO4 there are 29.45 grams of Ca present and there is 25.6 gram of total CaSO4 sample present, So, to calculate the exact value of calcium in this given sample is:
mass of Ca = total amount of sample*percentage of calcium in sample /100
M of Ca =25.6*29.45/100
M of Ca = 7.5392 grams
Thus, the correct procedure is given by 29.45 / 100 x 25.6 = 7.5392 grams
Tell me this why don't water stop my mouth from burning but milk or malk does this s for 32 points
Answer:
water spreads the spicy taste around your mouth, while milk does not and it helps the hot taste go away.
Explanation:
Answer:
water makes ur mouth burn more but milk it helps bc of what's in it
What is the difference between an atomic symbol and a chemical symbol?
Answer: A chemical symbol is a one- or two-letter designation of an element. Compounds are combinations of two or more elements. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.
Measurements show that unknown compound X has the following composition: element mass % chromium 68.4% oxygen 31.5% Write the empirical chemical formula of X.
Answer: The empirical formula of X is [tex]Cr_2O_3[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of Cr = 68.4 g
Mass of O = 31.5 g
Step 1 : convert given masses into moles.
Moles of Cr =[tex]\frac{\text{ given mass of Cr}}{\text{ molar mass of Cr}}= \frac{68.4g}{52g/mole}=1.31moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{31.5g}{16g/mole}=1.97moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Cr = [tex]\frac{1.31}{1.31}=1[/tex]
For O = [tex]\frac{1.97}{1.31}=1.5[/tex]
The simple whole number ratio of Cr : O= 2: 3
Hence the empirical formula is [tex]Cr_2O_3[/tex]
What happens when an electric charge moves
Answer:
When an electric charge moves, heat is dissipated due to the drift velocity hence current is induced
2.92 x 10^-15/
(5.6 x 10^-3) (4.16 x 10^9)
Answer:
3645.46
Explanation:
calculated
The United States National Weather Service reports pressure in mm of Hg. What's the pressure of 725 mmHg in Pa, millibars, and Torr?
A. 101.325 Pa, 966 millibar, 725 Torr
B. 100,000 Pa, 1000 millibar, 760 Torr
C. 96,657 Pa, 966 millibar, 725 Torr
D.100.000 Pa, 760 millibar. 725 Torr
Answer:
C. 96,657 Pa, 966 millibar, 725 Torr
Explanation:
The pressure of 725 mmHg in Pa, millibars, and Torr is 96,657 Pa, 966 millibar, 725 Torr. Hence option C is correct.
What is pressure?Pressure is defined as the force that is applied perpendicularly to an object's surface in relation to the area that it is dispersed over. Pressure can actually be a very good thing. Stress only occurs and has a fully negative impact when it continues to grow and that sensation of serenity and order is replaced with one of being out of control.
Given pressure = 725 mmHg
1 mmHg = 133.32 Pa
725 mmHg = 133.32 x 725 Pa
= 96,657 Pa
1 mmHg = 1.333 millibar
725 mmHg = 725 x 1.333 millibar
= 966 millibar
1 mmHg = 1 torr
725 mmHg = 725 Torr
Thus, the pressure of 725 mmHg in Pa, millibars, and Torr is 96,657 Pa, 966 millibar, 725 Torr. Hence option C is correct.
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If 8.50 g of phosphorus reacts with hydrogen gas at 2.00 atm in a 10.0-L container at 298 K, calculate the moles of PH3 produced as well as the total number of moles of gas present at the conclusion of the reaction.
Answer:
The moles of PH₃ produced are 0.2742 and the total number of moles of gas present at the end of the reaction is 0.6809.
Explanation:
Phosphorus reacts with H₂ according to the balanced equation:
P₄ (s) + 6 H₂ (g) ⇒ 4 PH₃ (g)
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
P₄: 1 moleH₂: 6 molesPH₃:4 molesBeing the molar mass of the compounds:
P₄: 124 g/moleH₂: 2 g/molePH₃: 34 g/moleThe following mass amounts of each compound participate in the reaction:
P₄: 1 mole* 124 g/mole= 124 gH₂: 6 mole* 2 g/mole= 12 gPH₃: 4 moles* 34 g/mole= 136 gAn ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
In this case you know:
P= 2 atmV= 10 Ln= ?R= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 298 KReplacing:
2 atm*10 L= n*0.082 [tex]\frac{atm*L}{mol*K}[/tex] *298 K
and solving you get:
[tex]n=\frac{2 atm*10 L}{0.082\frac{atm*L}{mol*K}*298 K }[/tex]
n=0.818 moles
The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
To determine the limiting reagent, you can use a simple rule of three as follows: if 6 moles of H₂ react with 124 g of P₄, 0.818 moles of H₂ with how much mass of P₄ will it react?
[tex]mass of P_{4}=\frac{0.818 moles of H_{2}*124 grams of P_{4}}{6 moles of H_{2}}[/tex]
mass of P₄= 16.90 grams
But 16.90 grams of P₄ are not available, 8.50 grams are available. Since you have less mass than you need to react with 0.818 moles of H₂, phosphorus P₄ will be the limiting reagent.
Then you can apply the following rules of three:
If 124 grams of P₄ produce 4 moles of PH₃, 8.50 grams of P₄, how many moles do they produce?[tex]moles of PH_{3} =\frac{8.5 grams of P_{4}*4 moles of PH_{3} }{124grams of P_{4}}[/tex]
moles of PH₃=0.2742
If 124 grams of P₄ react with 6 moles of H₂, 8.50 grams of P₄ with how many moles of H₂ do they react?[tex]moles of H_{2} =\frac{8.5 grams of P_{4}*6 moles of H_{2} }{124grams of P_{4}}[/tex]
moles of H₂= 0.4113
If you have 0.818 moles of H₂, the number of moles of gas H₂ present at the end of the reaction is calculated as:
0.818 - 0.4113= 0.4067
Then the total number of moles of gas present at the end of the reaction will be the sum of the moles of PH₃ gas and H₂ gas that did not react:
0.2742 + 0.4067= 0.6809
Finally, the moles of PH₃ produced are 0.2742 and the total number of moles of gas present at the end of the reaction is 0.6809.
The ideal gas equation gives the approximate amount of PH₃ produced
and the gas at the conclusion as 0.28 and 0.69 moles respectively.
Response:
First part:
The PH₃ gas produced is approximately 0.28 molesSecond part:
The number of moles of gas present at the conclusion of the reaction is approximately 0.69 molesWhat is the ideal gas equation, and how does it give the number of moles of gas present?Given:
Mass of phosphorus = 8.50 g
Pressure of hydrogen gas, P = 2.00 atm
Volume of hydrogen gas, V = 10.0–L
Temperature of the gas, T = 298 K
First part:
From the ideal gas equation, P·V = n·R·T, we have;
[tex]Number \ of \ moles, \ n = \mathbf{\dfrac{P\cdot V}{R \cdot T}}[/tex]
Where for the hydrogen gas, H₂, we have;
P = 2.00 atm
V = 10.0 L
T = 298 K
The universal gas constant, R = 0.08205 L·atm·mol⁻¹·K⁻¹
Which gives;
[tex]n = \mathbf{ \dfrac{2.00 \times 10.0}{0.08205 \times 298}} \approx 0.82[/tex]
The number of moles of H₂ in the reaction, n ≈ 0.82 moles
The equation of the reaction is; P₄(s) + 6H₂(g) [tex]\longrightarrow[/tex] 4PH₃(g)Therefore;
1 mole of P₄(s) and 6 moles of H₂(g) produces 4 moles of PH₃(g)
Molar mass of P₄ ≈ 123.9 g
Which gives;
Number of moles in 8.50 g of phosphorus = [tex]\frac{8.5}{123.9}[/tex] ≈ 0.069
0.069 moles of P₄ will react with 0.069 × 6 moles ≈ 0.41 moles of H₂ to produce 0.069 × 4 moles ≈ 0.28 moles of PH₃
Number of moles of PH₃ gas produced is approximately 0.28 molesSecond part:
The total number of moles of gas present at the conclusion of the reaction is therefore;
∑Gas ≈ 0.28 moles + (0.82 - 0.41) moles ≈ 0.69 molesLearn more about the ideal gas equation here:
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What is the poH of a
2.6 x 10-6 M H+ solution?
pOH = [?]
Answer:
pOH = 8.41
Explanation:
From the question given above, we obtained the following information:
Concentration of Hydrogen ion [H⁺] = 2.6×10¯⁶ M
pOH =?
Next, we shall determine the pH of the solution. This can be obtained as follow:
Concentration of Hydrogen ion [H⁺] = 2.6×10¯⁶ M
pH =?
pH = – Log [H⁺]
pH = – Log (2.6×10¯⁶)
pH = 5.59
Finally, we shall determine the pOH of the solution. This can be obtained as follow:
pH = 5.59
pOH =?
pH + pOH = 14
5.59 + pOH = 14
Collect like terms
pOH = 14 – 5.59
pOH = 8.41
Therefore, the pOH of the solution is 8.41
Answer:
8.41
Explanation:
How many protons, neutrons, and electrons does sulfur have
Answer:
Name
Sulfur
Atomic Mass
32.066 atomic mass units
Number of Protons
16
Number of Neutrons
16
Number of Electrons
16
Explanation:
Answer:
Explanation:
16 protons
16 electrons
16 neutrons
the earth's crust is part of which sphere?
Answer:
Lithosphere
Explanation:
The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.
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How would a long period without sunlight affect the food web? PLEZZ HELP MEH IF YOU WANT BRAINEIST AND LIKE COMMENTED
It would cause consumers to consume more food.
It would have no effect on the food web.
It would stop decomposers from breaking down matter.
It would stop producers from producing food.
Answer:
im pretty sure its the last one
Explanation:
if plants dont have sun light they will die because the sunlight gives them the nutrients to survive
The concentration of hydrogen peroxide solution can be determined by
titration with acidified potassium manganate(VII) solution. In this reaction
hydrogen peroxide is oxidised to oxygen gas. A 5.0 cm sample of hydrogen
peroxide solution was added to a volumetric flask and made to 250 cm
of the aqueous solution. A 25.0 cm sample of this solution was acidified
and reacted completely with 24 35 em of 0.0187 mol dm potassium
manganate(VII) solution
(ay Write a balanced equation for the reaction between acidified KMnO
solution and H.O.
(b) Calculate the concentration of the original H,O, solution in mol dm
The question is incomplete, the complete reaction equation is;
The concentration of a hydrogen peroxide solution can be determined by titration
with acidified potassium manganate(VII) solution. In this reaction the hydrogen
peroxide is oxidised to oxygen gas.
A 5.00 cm3 sample of the hydrogen peroxide solution was added to a volumetric flask
and made up to 250 cm3 of aqueous solution. A 25.0 cm3 sample of this diluted
solution was acidified and reacted completely with 24.35 cm3 of 0.0187 mol dm–3
potassium manganate(VII) solution.
Write an equation for the reaction between acidified potassium manganate(VII)
solution and hydrogen peroxide.
Use this equation and the results given to calculate a value for the concentration,
in mol dm–3, of the original hydrogen peroxide solution.
(If you have been unable to write an equation for this reaction you may assume that
3 mol of KMnO4 react with 7 mol of H2O2. This is not the correct reacting ratio.)
Answer:
2.275 M
Explanation:
The equation of the reaction is;
2 MnO4^-(aq) + 16 H^+(aq) + 5H2O2(aq) -------> 2Mn^+(aq) + 10H^+ (aq) + 8H2O(l)
Let;
CA= concentration of MnO4^- = 0.0187 mol dm–3
CB = concentration of H2O2 = ?
VA = volume of MnO4^- = 24.35 cm3
VB = volume of H2O2 = 25.0 cm3
NA = number of moles of MnO4^- = 2
NB = number of moles of H2O2 = 5
From;
CAVA/CBVB = NA/NB
CAVANB = CBVBNA
CB = CAVANB/VBNA
CB = 0.0187 * 24.35 * 5/25.0 * 2
CB = 0.0455 M
Since
C1V1 = C2V2
C1 = initial concentration of H2O2 solution = ?
V1 = initial volume of H2O2 solution = 5.0 cm3
C2 = final concentration of H2O2 solution= 0.0455 M
V2 = final volume of H2O2 solution = 250 cm3
C1 = C2V2/V1
C1 = 0.0455 * 250/5
C1 = 2.275 M
Which symbol can be used to indicate the pressure at which a chemical reaction is carried out?
25°C
OA
2 atm
Pt
Answer:
2 atm
Explanation:
The symbol 'atm' is used for pressure. Hence, the symbol used to indicate the pressure at which a chemical reaction is carried out can be, 2 atm.
find the weight of HNO_3 present in 20ml, 0.30 N
Answer:
mass of HNO₃ = 0.378 g
Explanation:
Normality = Molarity * number of equivalents
Molarity = Normality/number of equivalents
normality of HNO₃ = 0.30 N, Volume = 20 mL
HNO₃ ionizes in the following way:
HNO₃(aq) ----> H⁺ + NO₃⁻
Therefore, number of equivalents for HNO₃ is 1
molarity of HNO₃ = 0.30/1 =0.30 mol/dm³
Using the formula, molarity = number of moles/volume in liters
number of moles = molarity * volume
Number of moles of HNO₃ = 0.30 mol/dm³ * 20ml * 1 dm³ /1000 mL
number of moles = 0.006 moles
From the formula, mass = number of moles * molar mass
molar mass of HNO₃ = 63.0 g/mol
mass = 0.006 * 63
mass of HNO₃ = 0.378 g
The building blocks of DNA are like alphabet letters,
because they:
А: Are each associated with a particular sound
B: Can be used in a variety of languages
C: Each have an uppercase and a lowercase form
D: Spell out different instructions depending on their order
Help please
Please help!!! The person who gets it right gets brainlist
Answer:B because all of the atoms exploded AND GRAVITY WAS CREATED AND forced molecules together (God caused it btw)
Explanation:The BIBLE
HELP HELP HELP HELP
Which of the following elements is malleable and ductile?
A) Cobalt (27)
B) Nitrogen (7)
C) Arsenic (33)
the answer is Nitrogen.
How does energy from Earth’s interior affect surface changes?
Answer:
Energy produced deep inside Earth heats rock in the mantle. ... As it becomes less dense, the heated rock rises toward Earth's surface. The cooler, denser rock surrounding the heated rock sinks, as Figure 5 shows. In this way, heat inside Earth moves toward the cooler crust.
Explanation:
do you like my og name
Energy from Earth’s interior affect surface changes due to:
Earth heat transport occurs by conduction, mantle convection, hydrothermal convection, and volcanic advection. Thus, about 99% of Earth's internal heat loss at the surface is by conduction through the crust, and mantle convection is the dominant control on heat transport from deep within the Earth.Tectonic processes and flow in Earth's interior drive deformation of Earth's surface that can lead to destructive earthquakes, tsunamis, and volcanic eruptions.Learn more:
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What are the outcomes of the ice cap melting? Choose all that apply.
1. Light cannot be reflected back to the atmosphere
2. Sea level rises
3. Absorption of solar radiation leads to increase in ocean temperature
4. Ocean remains unaffected
Answer:
2. sea level rises sorry if it's wrong
whats the Number of molecules in 1.500 mole of H2O
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)
number of moles =1.500 mole
substituting all the given values in the above equation, we get
number of atoms/molecules=1.500 × 6.022×10²³(Avogadro number)
number of atoms/molecules =9.033×10²³molecules
Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.
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Investigate: Press Reset. Start with 2.000 moles of sulfur, then press Start. How many atoms do you think this amount represents
Answer:
1.204428 * 10^24 atoms
Explanation:
Number of moles = 2 mol
Number of atoms = ?
The relationship between moles and atoms is given by the avogadro's umber. This is the number of units in one mole of a substance. The units can be atoms, ions etc In this case it is atoms. The number is equal to 6.02214076 * 10^23
This means;
1 mol = 6.02214076 * 10^23
2 mol = x
Upon solving for x,
x = 2 * 6.02214076 * 10^23
x = 12.04428 * 10^23
x = 1.204428 * 10^24 atoms
A light bulb consumes energy at a rate of 80
joules per second . How long in
seconds will it take for the light bulb to consume 2.30 ~ 105
in energy?
Answer:
2875 s
Explanation:
From the question given above, the following data were obtained:
Power (P) = 80 J/s
Energy (E) = 2.3×10⁵ J
Time (t) = ?
Power can simply be defined as the rate at which energy is used. Mathematically, power is expressed as:
Power = Energy / time
P = E/t
With the above formula, we can obtain the time taken for the bulb to consume 2.3×10⁵ J. This can be obtained as follow:
Power (P) = 80 J/s
Energy (E) = 2.3×10⁵ J
Time (t) = ?
Power = Energy / time
P = E/t
80 = 2.3×10⁵ /t
Cross multiply
80 × t = 2.3×10⁵
Divide both side by 80
t = 2.3×10⁵ / 80
t = 2875 s
Therefore, it will take 2875 s for the bulb to consume 2.3×10⁵ J of energy.
What is the molarity of a solution of 10% by mass cadmium sulfate, CdSO4 (molar mass = 208.46 g/mol) by mass? The density of the solution is 1.10 g/mL.
a. 0.528 M
b. 0.436 M
c. 0.479 M
d. 0.048 M
e. 22.9 M
Answer:
a. 0.528 M .
Explanation:
Hello!
In this case, since the given by-mass percent can be written as:
[tex]\frac{10gCdSO_4}{100g\ sol}[/tex]
By using the density and molar mass of the solute, cadmium sulfate, we can compute the molarity, by also making sure we convert from mL to L of solution:
[tex]M=\frac{10gCdSO_4}{100g\ sol}*\frac{1molCdSO_4}{208.46gCdSO_4} *\frac{1.10g\ sol}{1mL\ sol}*\frac{1000mL}{1L} \\\\ M=0.528M[/tex]
Thereby, the answer is a. 0.528 M .
Best regards.
The molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.
To calculate molarity we need to find out how many moles of CdSO4 are present in the solution.
Given:
Mass of [tex]CdSO_4[/tex]= 10% by mass of the solutionMolar mass of [tex]CdSO_4[/tex] = 208.46 g/molDensity of the solution = 1.10 g/mLWe need to calculate the mass of [tex]CdSO_4[/tex]:
Mass of [tex]CdSO_4[/tex] = (10% / 100%) * Total mass of the solution
Mass of [tex]CdSO_4[/tex] = (10 / 100) * 1000 g (since the volume is 1 L, and the density is 1.10 g/mL)
Mass of [tex]CdSO_4[/tex] = 100 g
So, the number of moles of CdSO4:
Number of moles of [tex]CdSO_4[/tex] = Mass of CdSO4 / Molar mass of CdSO4
Number of moles of [tex]CdSO_4[/tex] = 100 g / 208.46 g/mol
Number of moles of [tex]CdSO_4[/tex] ≈ 0.479 moles
Then, we calculate the molarity of the solution:
Molarity = Number of moles of CdSO4 / Volume of the solution (in liters)
Molarity = 0.479 moles / 1 L
Molarity ≈ 0.479 M
Hence, the molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.
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What should a student do to set a goal? Check all that apply.
Create a plan.
Make a schedule.
Schedule lots of tasks.
Rush into the goal.
Pace him or herself.
Answer:
create a plan
the ways of of a student to set a goal
1. Write clear and measurable goals
2.Create a specific plan for each goal
3.Read your goals daily and visualize yourself accomplishing them
4. Reflect yourself to see if you are on target
5. Revise your action plans if needed.
1.)make a plan
2.)make a schedule
5.)pace him or herself
