Using ideal gas equation,

Here,
P denotes pressure
V denotes volume
n denotes number of moles of gas
R denotes gas constant
T denotes temperature
The values at STP will be:
P=1 atm
T=25 C+273 K =298.15K
V=663 ml=0.663L
R=0.0821 atm L mol ⁻¹
Mass of gas given=1.25 g g
Molar mass of gas given=?


Putting all the values in the above equation,

Molar mass of the gas=46.15
Answer:
1)non.metals gain electron but metals lose electron.
2)metals are good conductor of heat and electricity but non.meatals are bad conductor of heat and electricity.
3)most of metals are shiny but non .metals are not.
Answer:
Gas is sometimes measured in cubic feet at a temperature of 60 degrees Fahrenheit and an atmospheric pressure of 14.7 pounds per square inch. Gas production from wells is discussed in terms of thousands or millions of cubic feet (Mcf and MMcf). Resources and reserves are calculated in trillions of cubic feet (Tcf).
I believe it is because, Lead has a higher boiling point than zinc. by the time Lead melts and becomes a liquid, the temperature is way higher than the boiling point of Zinc therefore, Zinc becomes a gas.