Question

Write the ground-state electron configuration for each atom. After each atom is its atomic number in parentheses. (a) Sodium (11) (b) Magnesium (12) (c) Oxygen (8) (d) Nitrogen (7)

Short answer

Question: Write the ground-state electron configuration for the following atoms: (a) Sodium, (b) Magnesium, (c) Oxygen, (d) Nitrogen. Answer: (a) Sodium: 1s² 2s² 2p⁶ 3s¹, (b) Magnesium: 1s² 2s² 2p⁶ 3s², (c) Oxygen: 1s² 2s² 2p⁴, (d) Nitrogen: 1s² 2s² 2p³.

Step-by-step solution

Determine the number of electrons

As sodium has an atomic number of 11, it contains 11 electrons in its ground state.

Follow the Aufbau principle and fill the orbitals

According to the Aufbau principle, we will fill the orbitals in order of increasing energy levels. For sodium: 1s^2: The first two electrons go into the 1s orbital. 2s^2: The next two electrons go into the 2s orbital. 2p^6: The following six electrons go into the 2p sublevel, completely filling it. 3s^1: The last electron goes into the 3s orbital. So, the ground-state electron configuration for sodium is: 1s^2 2s^2 2p^6 3s^1 (b) Magnesium (12)

Determine the number of electrons

Magnesium has an atomic number of 12, so it has 12 electrons in its ground state.

Follow the Aufbau principle and fill the orbitals

Following the Aufbau principle for magnesium: 1s^2: Fill the 1s orbital. 2s^2: Fill the 2s orbital. 2p^6: Fill the 2p sublevel. 3s^2: Fill the 3s orbital completely. The ground-state electron configuration for magnesium is: 1s^2 2s^2 2p^6 3s^2 (c) Oxygen (8)

Determine the number of electrons

Oxygen has an atomic number of 8, so it has 8 electrons in its ground state.

Follow the Aufbau principle and fill the orbitals

Following the Aufbau principle for oxygen: 1s^2: Fill the 1s orbital. 2s^2: Fill the 2s orbital. 2p^4: Fill four of the available six spaces in the 2p sublevel. The ground-state electron configuration for oxygen is: 1s^2 2s^2 2p^4 (d) Nitrogen (7)

Determine the number of electrons

Nitrogen has an atomic number of 7, so it has 7 electrons in its ground state.

Follow the Aufbau principle and fill the orbitals

Following the Aufbau principle for nitrogen: 1s^2: Fill the 1s orbital. 2s^2: Fill the 2s orbital. 2p^3: Fill three of the available six spaces in the 2p sublevel. The ground-state electron configuration for nitrogen is: 1s^2 2s^2 2p^3