G. H2S contains two hydrogen atoms
The answer is: when the aim is to show electron distributions in shells
An orbital notation is more appropriate if you want to show how the electrons of an atom are distributed in each subshell. This is because there are some atoms that have special electronic configurations that aren't obvious in just written configurations.
Water is your answer!!!!!!!!!
B the atomic number is 20 and then you subtract atomic mass to find the neutrons
