Question

use the periodic to fill in the numbers in the electron configurations shown below. b: 1s² 2s^a 2p^b a = b =

Explanation:

Step1: Recall electron - configuration rules

Electron sub - shells fill in a specific order. The s sub - shell can hold a maximum of 2 electrons and the p sub - shell can hold a maximum of 6 electrons. For boron (B), the atomic number is 5, which means it has 5 electrons.

Step2: Determine the value of A

The 2s sub - shell fills after the 1s sub - shell. Since the s sub - shell can hold a maximum of 2 electrons, for boron, the number of electrons in the 2s sub - shell, A = 2.

Step3: Determine the value of B

We know that boron has 5 electrons. The 1s sub - shell has 2 electrons and the 2s sub - shell has 2 electrons. So the number of electrons in the 2p sub - shell, B=5-(2 + 2)=1.

Answer:

A = 2
B = 1