Subtopic 2.3

For which element does its ground state atom have the greater number of unpaired electrons?

• Phosphorus (Z=15)

• Titanium (Z=22)

• Iron (Z=26)

• Zinc (30)

Electron configuration of gallium is [Ar] 3d¹⁰ 4s² 4p¹. The order of electron removal in the formation of Ga³⁺ from first electron to second electron to third electron is is...

(Tips: Removing of electron is starting from the outermost shell @highest value of n)

• 4p , 4s , 3d

• 4p , 4s , 4s

• 4s , 4s ,4p

• 3d , 4s , 4s

Which of the following does not obey Hund's Rule?

• 
• 
• 
• 

According to Aufbau Principle, the electrons need to be filled in energy level 4s first then 3d.

When removing the electrons in the outermost shell of an atom that has 4s and 3d energy levels, the electron needs to be removed from which energy level first?

• 4s

• 3d

• 3p

• 1s

An atom containing eight electrons in 3d orbital are arranged according to....

• Aufbau Principle

• Hund's Rule

• Pauli Exclusion Principle

An element Z has an electronic configuration as follows:

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵

Which of the following statement(s) is/are true?

• The element is in d-block.

• The element tends to form Z^-.

• The element is in period 4 of the periodic table.

Which one of these is the definition of Aufbau's Principle?

• In a given set of orbitals of equivalent energy (degenerate orbitals), electrons tend to occupy the orbitals singly first before pairing up.

• No two electrons in an atom can have the same set of four quantum numbers.

• The electrons must occupy available orbitals of lower energy first before they filled orbitals of higher energy.

Which one of these is the definition of Hund's Principle?

• In a given set of orbitals of equivalent energy (degenerate orbitals), electrons tend to occupy the orbitals singly first before pairing up.

• No two electrons in an atom can have the same set of four quantum numbers.

• The electrons must occupy available orbitals of lower energy first before they filled orbitals of higher energy.

Which one of these is the definition of Pauli Exclusion Principle?

• In a given set of orbitals of equivalent energy (degenerate orbitals), electrons tend to occupy the orbitals singly first before pairing up.

• No two electrons in an atom can have the same set of four quantum numbers.

• The electrons must occupy available orbitals of lower energy first before they filled orbitals of higher energy.

How many anomalous cases in electronic configuration that exceptional to Aufbau's Principle?

• 1

• 2

• 3

• 4