I don't understand how you would find these . . .?

Question

a. how many electrons are in a neutrally charged potassium atom?

b. how many electrons are in a +1 charged potassium atom?

c. how many electrons are in a -2 charged sulfur atom?

Answer 1

a. We look at the entire configuration: 1s2 2s2 2p6 3s2 3p6 4s2

From the 1s, 2s, 2p, 3s, 3p, and 4s subshells we have 20 total electrons. The number after these shells represent the # electrons each shell can hold.

b. without even rewriting this diagram I know that one electron has been lost so an extra proton is unbalanced alone leaving a positive charge. There are 19 electrons.

c. S has: 1s2 2s2 2p6 3s2 3p4

    S2- has: 1s2 2s2 2p6 3s2 3p6  -------  There are 18 electrons.

    Now there are two extra electrons in sulfur giving it an unbalanced

    2 x electrical charge.

It's hard I had trouble too but keep working at it it's much easier with time!

    

Answer 2

a:  Potassium is the 19th element, making its atomic number 19- means there are 19  protons and electrons since it is a neutral

b.  To be potassium, it must have 19 protons, if it loses 1 electron, it becomes posively charged, therefore 18 elecrons would result in +1

c. Similarly, the atomic number of sulfur is 16, so as neutral it has 16 protons and 16 neutrons, a -2 charge means it gained to electrons- so 18