B. The surface of a silver cup turns black when it is exposed to air.
We have that the the density of FeS is mathematically given as
From the question we are told
Iron(II) sulfide has a primitive <em>cubic</em> unit cell with <em>sulfide</em> ions at the <em>lattice points.</em>
The ionic radii of iron(II) ions and sulfide ions are 88 pm and 184 pm, respectively.
What is the density of FeS (in g/cm3)?
<h3>
Density</h3>
Generally the equation for the Velocity is mathematically given as

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Answer:
P₅O₁₂
<em>Explanation: </em>
Assume that you have 100 g of the compound.
Then you have 44.7 g P and 55.3 g O.
1. Calculate the <em>moles</em> of each atom
Moles of P = 44.7 × 1/30.97 = 1.443 mol Al
Moles of O = 55.3 × 1/16.00 = 3.456 mol O
2. Calculate the <em>molar ratios</em>.
P: 1.443/1.443 = 1
O: 3.456/1.443 = 2.395
3. Multiply by a number to make the ratio close to an integer
P: 5 × 1 = 5
O: 5 × 2.395 = 11.97
3. Determine the <em>empirical formula
</em>
Round off all numbers to the closest integer.
P: 5
O: 12
The empirical formula is <em>P₅O₁₂</em>.
2.2311 moles of gas are there in a 50. 0 l container at 22. 0 °c and 825 torrs.
<h3>What is an ideal gas?</h3>
An Ideal gas is a hypothetical gas whose molecules occupy negligible space and have no interactions, and which consequently obeys the gas laws exactly.
Assuming the gas is ideal, we can solve this problem by using the following equation:
PV = nRT
Where:
P = 825 torr ⇒ 825 / 760 = 1.08 atm
V = 50 L
n = ?
R = 0.082 atm·L·mol⁻¹·K⁻¹
T = 22 °C ⇒ 22 + 273.16 = 295.16 K
We input the data:
1.08 atm x 50 L = n x 0.082 atm·L·mol⁻¹·K⁻¹ x 295.16 K
And solve for n:
24.20312
n = 2.2311 mol
Hence, 2.2311 moles of gas are there in a 50. 0 L container at 22. 0 °c and 825 torrs.
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Among solids, liquids, and gases, solids generally have the highest entropy because solid particles are the least mobile, and entropy is inversely related to mobility of particles.