Electron Configurations

What is the maximum number of electrons that can occupy the s orbital at any given energy level?

• 1

• 2

• 6

• 8

Which of the following electron configurations corresponds to an atom of chlorine (Cl)?

• 1s² 2s² 2p⁶ 3s² 3p⁵

• 1s² 2s² 2p⁶ 3s² 3p⁶

• 1s² 2s² 2p⁶ 3s² 3p⁴

• 1s² 2s² 2p⁶ 3s¹ 3p⁵

How many valence electrons does an atom of sulfur (S) have?

• 4

• 6

• 16

• 2

Which of the following elements has a completely filled d subshell in its ground state?

• Iron (Fe)

• Zinc (Zn)

• Copper (Cu)

• Chromium (Cr)

Which of the following is the correct electron configuration for the element with atomic number 20 (Calcium)?

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

• 1s² 2s² 2p⁶ 3s² 3p⁶ 3d²

• 1s² 2s² 2p⁶ 3s² 3p⁴ 4s²

• 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹ 4s²

How many unpaired electrons are in the ground state of nitrogen (N)?

• 1

• 2

• 3

• 0

Which of the following elements has the electron configuration 1s² 2s² 2p⁶ 3s² 3p¹?

• Aluminum (Al)

• Silicon (Si)

• Boron (B)

• Sodium (Na)

What is the electron configuration for the valence shell of an atom of argon (Ar)?

• 3s² 3p⁴

• 3s² 3p⁶

• 3s¹ 3p⁵

• 3s² 3p³

Which of the following is the correct order of filling the orbitals according to the Aufbau principle?

• 1s, 2s, 2p, 3s, 3p, 4s, 3d

• 1s, 2p, 2s, 3s, 3p, 4s, 3d

• 1s, 2s, 3s, 2p, 3p, 4s, 3d

• 1s, 2s, 2p, 3p, 3s, 4s, 3d

Which of the following elements has two unpaired electrons in its ground state?

• Carbon (C)

• Oxygen (O)

• Neon (Ne)

• Magnesium (Mg)