Questions: Phosphorous ( P ) has atomic number of 15 . How many electrons are in its 1 st shell?

Transcript text: Phosphorous ( P ) has atomic number of 15 . How many electrons are in its 1 st shell?

Solution

Solution Steps

Step 1: Identify the Atomic Number of Phosphorus

Phosphorus (P) has an atomic number of 15. This means it has 15 protons and, in a neutral atom, 15 electrons.

Step 2: Understand Electron Shell Configuration

Electrons are arranged in shells around the nucleus. The first shell can hold a maximum of 2 electrons, the second shell can hold up to 8 electrons, and the third shell can hold up to 18 electrons.

Step 3: Determine the Number of Electrons in the 1st Shell

Since the first shell can hold a maximum of 2 electrons, and electrons fill the lowest energy levels first, the 1st shell of phosphorus will have 2 electrons.