Question

1. complete the ground state orbital - filling diagram and write the corresponding electron configurations below.

extension questions
model 3 - orbital diagram for an atom of element x

1. consider the orbital diagram in model 3.

a. how many electrons are there in one atom of element x?
b. identify element x and provide its ground - state electron configuration. assume the atom is neutral.

Explanation:

Part a: Number of electrons in element X

Step 1: Analyze 1s orbital

The 1s orbital has 2 electrons (paired, $\uparrow\downarrow$).

Step 2: Analyze 2s orbital

The 2s orbital has 2 electrons (paired, $\uparrow\downarrow$).

Step 3: Analyze 2p orbitals

• First 2p orbital: 1 electron ($\uparrow$)
• Second 2p orbital: 2 electrons (paired, $\uparrow\downarrow$)
• Third 2p orbital: 2 electrons (paired, $\uparrow\downarrow$)

Total 2p electrons: $1 + 2 + 2 = 5$

Step 4: Sum all electrons

Total electrons = 1s + 2s + 2p = $2 + 2 + 5 = 9$

Part b: Identify element X and its electron configuration

Step 1: Determine atomic number

The number of electrons (9) equals the atomic number, so element X is fluorine (F).

Step 2: Write electron configuration

Using orbital filling: 1s² (2 electrons), 2s² (2 electrons), 2p⁵ (5 electrons).
Thus, electron configuration: $1s^2 2s^2 2p^5$

Answer:

s:
a. $\boldsymbol{9}$ electrons.
b. Element X is $\boldsymbol{\text{Fluorine (F)}}$, electron configuration: $\boldsymbol{1s^2 2s^2 2p^5}$