Which principle explains the order in which atomic orbitals are filled?

A. Hund's Rule

B. Pauli Exclusion Principle

C. Aufbau Principle

D. Heisenberg Uncertainty Principle

Which of the following elements has an electron configuration exception?

A. Iron

B. Chromium

C. Zinc

D. Nickel

How many unpaired electrons are present in the ground state of oxygen?

A. 1

B. 2

C. 3

D. 4

Which rule states that electrons will fill degenerate orbitals singly before pairing up?

A. Pauli Exclusion Principle

B. Hund's Rule

C. Aufbau Principle

D. Heisenberg Uncertainty Principle

Which of the following is NOT a valid representation of electron configurations using arrows?

A. ↑↓ ↑↓ ↑↓ ↑

B. ↑↓ ↑↓ ↑ ↑

C. ↑↓ ↑↓ ↑↓ ↑↓

D. ↑↓ ↑↓ ↑↓ ↓↑

a) Explain the Aufbau principle and its significance in determining the order in which atomic orbitals are filled. [3]

b) Using the Aufbau principle, determine the electron configuration for an atom with an atomic number of 11. [2]

a) Define the Pauli Exclusion Principle and explain its implications for electron filling in orbitals. [3]

b) How does the Pauli Exclusion Principle dictate electron spin in an orbital? [2]

a) Describe how electron configurations can be represented using arrows. [2]

b) What is the significance of using arrow representations in visualising electron arrangements in orbitals? [3]

a) What is Hund's rule and how does it affect the filling of electrons in degenerate orbitals? [3]

b) Using Hund's rule, describe the electron configuration of oxygen. [2]

c) Why is it energetically favourable for electrons to occupy separate degenerate orbitals before pairing up? [2]

a) How can the electron configuration of an element help in predicting its chemical properties? [3]

b) Explain the electron configuration of chromium and why it's an exception to the general rules. [3]

c) Why do some elements like chromium have unexpected electron configurations? [2]

For which of the following elements is the 4s subshell filled before the 3d subshell?

A. Calcium

B. Scandium

C. Titanium

D. Vanadium

Which principle states that no two electrons in an atom can have the same set of four quantum numbers?

A. Hund's Rule

B. Pauli Exclusion Principle

C. Aufbau Principle

D. Heisenberg Uncertainty Principle

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

A. Copper

B. Iron

C. Zinc

D. Nickel

What is the significance of representing electron configurations using arrows?

A. To indicate the number of protons

B. To visualise electron arrangements in orbitals

C. To represent the atomic mass

D. To show the atomic radius

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

A. Chromium

B. Manganese

C. Iron

D. Cobalt

a) Describe the significance of the s, p, d, and f orbitals in electron configurations. [3]

b) How many electrons can each type of orbital hold? [2]

c) Using the knowledge of orbitals, determine the electron configuration of phosphorus. [2]

a) What is meant by the term "valence electron"? [2]

b) How do valence electrons determine the chemical reactivity of an element? [3]

c) Using electron configurations, explain why noble gases are generally unreactive. [2]

a) What is the significance of the principal quantum number in electron configurations? [2]

b) Describe the four quantum numbers and their roles in defining the state of an electron in an atom. [4]

c) How does the magnetic quantum number differ for s, p, and d orbitals? [3]

d) Using the knowledge of quantum numbers, explain why the 4s orbital fills before the 3d orbital. [3]

a) What are the electron configurations for chromium and copper, and why are they considered exceptions? [3]

b) Explain the concept of electron shielding and its effect on atomic size. [3]

c) How does electron configuration influence an element's position in the periodic table? [3]

d) Why do transition metals often have similar properties, and how is this related to their electron configurations? [3]

a) Describe the difference between core electrons and valence electrons. [2]

b) How do core electrons influence the chemical reactivity of an atom? [3]

c) Using electron configurations, explain why elements in the same group of the periodic table have similar chemical properties. [3]

d) Why do ions form, and how is this related to electron configurations? [4]