Question

use the periodic to fill in the numbers in the electron configurations shown below.

\\(b: 1s^2 2s^a 2p^b\\)

\\(a = \\)

\\(b = \\)

Explanation:

Identify the element and its atomic number

The question asks to fill in the electron configuration for the element Boron (\(\text{B}\)).
Boron has an atomic number of \(Z = 5\), which means a neutral Boron atom has 5 electrons.

Determine the electron configuration

Using the Aufbau principle, electrons fill orbitals in order of increasing energy:

1. The \(1s\) subshell is filled first with 2 electrons: \(1s^2\).
2. The \(2s\) subshell is filled next with 2 electrons: \(2s^2\).
3. The remaining 1 electron enters the \(2p\) subshell: \(2p^1\).

Thus, the full configuration is \(1s^2 2s^2 2p^1\).

Match with the given variables

Comparing \(1s^2 2s^2 2p^1\) to the template \(1s^2 2s^A 2p^B\):

• \(A = 2\)
• \(B = 1\)

Answer:

Use the periodic table to fill in the numbers in the electron configurations shown below.

\(\text{B}: 1s^2 2s^A 2p^B\)

\(A =\) <blank>2</blank>

\(B =\) <blank>1</blank>