Answer
a) Z=20, symbol is Ca, name is Calcium
b) 4th period.
c) Alkaline earth metals.
d) 8
e) 12
f) 0
Work Step by Step
From the given data we can write the electronic configuration as;
1s$^{2}$2s$^{2}$2p$^{6}$3s$^{2}$3p$^{6}$4s$^{2}$.
Given that the atom is neutral,
so number of electrons= atomic number=20.
Highest principal quantum number is 4, hence the atom is in 4th period.
Since the last electron enters in s orbital and it is completely filled the atom belongs to alkaline earth metals.
Number of electrons in each sub-shell is clear from electronic configuration.
