Question

storyline 1 exam
an atom of bromine has 35 electrons. these electrons are present in energy shells around the nucleus. what is the electron configuration of bromine?
2, 8, 8, 17
2, 8, 18, 7
2, 8, 18, 1
2, 8, 18, 35

Explanation:

Step1: Recall electron - shell capacity rules

The first shell can hold a maximum of 2 electrons, the second shell can hold a maximum of 8 electrons, and the third shell can hold a maximum of 18 electrons.

Step2: Calculate electrons in each shell

• First shell: 2 electrons.
• Second shell: 8 electrons.
• Third shell: 18 electrons.
• Remaining electrons for the fourth shell: \(35-(2 + 8+18)=7\) electrons.

Answer:

2, 8, 18, 7