Answer: last one is right
Explanation: atoms of same element have always same number of protons but may have several isotopes which have different number of neutrons.
Answer:
The chemical formula of the gas is
.
Explanation:
The difference between the container with gas and empty container is equal to the mass of the gas.
Let the gas be 
Mass of the gas = m
Molar mass of diatomic gas = M
Pressure of the gas = P = 1.80 atm
Volume of the gas = V = 4.6 L
Temperature of the gas= T = 27.0 C = 27.0 + 273 K = 300 K
Moles of diatomic gas = n = 
Using ideal gas equation:



Atomic mass of the element X = 
The element is nitrogen and the diatomic gas is
.
Answer:1kg. Explanation: ( b is the symbol for molality, and molality is the number of moles of solute per kilogram of solvent). b=nm. 0.5=0.5m. m=1kg.
Explanation:
Here are the answers:
1) C
2) A