How does an element’s atomic number help us in determining the electron configuration for an atom?

(1).. atomic # = # protons

(2).. if the atom is neutral, # protons = # electrons

(3).. there is a pattern to how electrons fill.

(4).. the electronic configuration depends on that filling pattern

I am assuming you are not doing anything too advanced yet.

The Atomic Number is the amount of protons in a given nucleus.

The number of protons and electons is a 1:1 Ratio unless it is an Ion.

Ion: An atom with more or less electons than protons.

So because the atomic number is linked to electrons, you will be able to figure out the electron configuration.

for example:

K (Portassium) has an atomic number of 19. So the amount of electrons is also 19.

So you fill in the shells.

2,8,8,1

P.S If you are doing A-level or equivalent the subshells are:

1s^2 2s^2 2p^6 3s^2 3p^6 4s^1

You will not have to know about subshells if you have not been taught them.

If the atom is in the ground state then

Atomic no of element = No of the electrons

Thus if we know the no of electrons present in an atom , we can also find its electronic configuration.