Protons have a mass of 1
Neutrons have a mass of 1
So 13*1 + 14*1 = Mass number 27
CFC-11 is typically the CFC with the shortest atmospheric lifetime.
1- false
2- true
3- true
4- false
5- true
6- false
7- true
8- true
9- true
10- false
Hope it helps :)