How many valence electrons in each of the following?
a) Ca
Answer
2 valence electrons
Explanation
If we complete the table below for a calcium atom it is
Element
|
Nuclear
Charge
|
Electron
Configuration
|
Inner Core
Electrons
|
Valence
Electrons
|
Ca
|
20
|
1s22s22p63s23p64s2
|
18
|
2
|
Valence electrons are those electrons in the outer most shell. In the case
of calcium the outer most shell is the n = 4 shell. There are 2 electrons
in the fourth shell; the 2 in the s subshell.