How many atoms are there in 90.2 grams of selenium?
Answers
90.2 × 78.96 = 7122.2 moles
Number of moles multiplied by avogadros number gives number of atoms
7122.2 × 6.022 × 10^{23} = 4.289×10^{27} atoms
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Gabriella weighs 450 N. She climbs a flight of stairs to a height of 3 m. It takes her 5 seconds. How much work does Gabriella do when she climbs the stairs?A. 150 J B. 270 J C. 1350 J D. 2250 J
When an individual has an energy surplus, he or she stores the extra energy as: A. nucleic acids. B. lipids. C. None of the answer options is correct. D. carbohydrates. E. proteins.
Answers
When a gas condenses to liquid the process is exothermic with the release energy and the enthalpy change is negative. As liquid has more ordered structure than gas, the entropy, which is the measure of disorder decreases or ∆ S has a negative value.
Free energy is given by the Gibb's free energy equation,
∆G = ∆H –T∆S
For a process to be spontaneous ∆ G must be negative.
∆H is negative and ∆S is negative, so the magnitude of |T∆S| should be less than the magnitude of |∆H| in that way ∆G is always negative.
|T∆S| should be less than the magnitude of |∆H|, so to favor that T should be low. The process is spontaneous at a lower temperature than at a higher temperature.
B. metal
C. clay
D. wax
Answers
The right answer is wax.
The waxes are of synthetic, natural, animal or plant origin composed of long and branched chains which gives them a microcrystalline structure. This results in a soft, white, non-translucent substance whose melting temperature is arround 70 ° C.
The melt temperature of the clay exceeds 1000 ° C.
It is clear that wood and metal are not used for low temperature molding.
Answers
Ca3(PO4)2
Answers
There will be two atoms of phosphorus in the 1.75 mol of calcium phosphate.
What are atoms?
Atoms are the smallest unit of matter. In a chemical reaction, the number of atoms shows the quantity of an element in the compound or reaction. Phosphorus is a chemical element that is preset in the periodic table.
In calcium phosphate, Ca3(PO4)2, the number of atoms can be calculated by counting the number of moles that is given in the equation.
The number of atoms of calcium is 3, and the number of phosphorus atoms is 2.
Now given the 1.75 mol of calcium phosphate, so the number of atoms of phosphorus will be the same in any number of moles of calcium phosphate. So there will be 2 atoms of phosphorus in the given equation.
Thus, the number of atoms is two.
To learn more about atoms, refer to the below link:
#SPJ2
Answer:
It has 2 phosphorus atoms in 1 mol
so for 1.75 mol =2×1.75
Explanation:
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Answers
Answer:
Explanation:
We know that in 1 mole of any substances there are atoms
This number () is a constant that is known as the avogadros number
if we know how many atoms are in a mole of chromium to calculate how many there are in 11.9 moles we apply a simple rule of three
In 11.9 moles of chrome there are atoms
Given # of moles * molar mass (g) per mol = Mass (g)
This gives us 11.9 x 51.9962 (g) per mol.
618.75 moles
b. sugar.
c. water.
d. vinegar.