U1: Electron Configurations: Mastery Test

Match the following statements with the correct conditions according to the Pauli exclusion principle.

• Two electrons can occupy the same orbital if they are alike in all their properties

• only if there is no place else to put them

• Two electrons can occupy the same orbital if they have opposite spins

• only if they are alike in all their properties

• Two electrons cannot occupy the same orbital

• only if they have opposite spins

• Two electrons can occupy the same orbital

• only if they have the same spin

Select the correct answer. What does Hund's rule state?

• An orbital can contain two electrons only if the electrons have opposite spins.

• An orbital can contain two electrons only if all other orbitals at the sublevel are empty.

• An orbital can contain two electrons only if the electrons have different energy levels.

• An orbital can contain two electrons only if all other orbitals in that sublevel contain at least one electron.

What is the position of an element in the periodic table if its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁵?

• It's a group 5A element.

• It's a group 6A element.

• It's a group 3A element.

• It's a group 7A element.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The electron configuration that represents the element carbon (atomic number 6) is (a)  

• 1s² 2s² 2p⁶
• 1s² 2s² 2p⁴
• 1s² 2s² 2p²
• 1s² 2s²

Tags

NGSS.HS-PS1-1

Match the following orbitals with their corresponding series:

• First transition series

• 2s

• Second transition series

• 3d

• Fourth transition series

• 2p

• Third transition series

• 3s

Select the correct answer. Why do electrons enter the 4s orbital before entering the 3d orbital?

• because the 3d orbital is at lower energy level

• because both the 4s and 3d orbitals are at the same energy level

• because the 4s orbital is at a lower energy level

• because the 4s orbital is at a higher energy level

The noble gas configuration for silicon is (a)  

• [Ne] 3s²3p¹
• [Ar] 4s¹
• [Kr] 5s¹
• [Ne] 3s²3p²

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Select the correct answer. What is the magnetic quantum number value for an element with n = 1?

• -1, 0, +1

• 0

• -2, -1, 0, +1, +2

• -2, -1, 0

Select the correct answer. Which element has three unpaired electrons in its p orbital?

• carbon (atomic number 6)

• oxygen (atomic number 8)

• nitrogen (atomic number 7)

• beryllium (atomic number 4)

Tags

NGSS.HS-PS1-1

Select the correct answer. What does the sign ↑ represent with respect to electrons?

• opposite spin of two electrons

• different principal energy levels of two electron

• distance of two electrons from the nucleus

• attraction between two electrons