<u>Answer:</u> The edge length of the unit cell is 0.461 nm
<u>Explanation:</u>
We are given:
Atomic radius of iridium = 0.163 nm
To calculate the edge length, we use the relation between the radius and edge length for FCC lattice:

Putting values in above equation, we get:

Hence, the edge length of the unit cell is 0.461 nm
A) B). That’s it I hope it’s help.
<h3>Answer:</h3>
The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).
<h3>Solution:</h3>
According to Boyle's Law, " <em>The Volume of a given mass of gas at constant temperature is inversely proportional to the applied Pressure</em>". Mathematically, the initial and final states of gas are given as,
P₁ V₁ = P₂ V₂ ----------- (1)
Data Given;
P₁ = 500 mmHg
V₁ = 9.0 mL
P₂ = 750 mmHg
V₂ = ??
Solving equation 1 for V₂,
V₂ = P₁ V₁ / P₂
Putting values,
V₂ = (500 mmHg × 9.0 mL) ÷ 750 mmHg
V₂ = 6.0 mL
<h3>Result:</h3>
The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).