Answer : The mass of sample is, 267.5 grams.
Explanation :
Density : It is defined as the mass of a substance contained per unit volume.
Formula used :

Given:
Volume of Pb = 
Density of Pb = 
Now put all the given values in the above formula, we get the mass of Pb.


Therefore, the mass of sample is, 267.5 grams.
Answer:
Real gas particles have significant volume
Real gas particles have more complex interactions than ideal gas particles.
Explanation:
An ideal gas is an imaginary concept and a gas behaves almost ideally at certain pressure and temperature conditions.
The gas in real deviates from the ideal behavior as some of the assumptions made for ideal gases are not true in case of real gases.
Real gas particles have significant volume as compared to vessel unlike ideal gases.
There are interactions present in between real gas molecules at high pressure conditions.
It has a density lower than 1
C.) Copper ( Cu, atomic number) is an element which is malleable as well good conductors of heat and electricity. Hope this helps!