Hund's Rule Demystified: Electron Configuration Challenge

1. How many electrons can be accommodated in the s orbital?

2

4

6

8

The s orbital can accommodate a maximum of 2 electrons. This is because the s orbital has a single orientation and can hold two electrons with opposite spins.

Explanation

The s orbital can accommodate a maximum of 2 electrons. This is because the s orbital has a single orientation and can hold two electrons with opposite spins.

2. Which of the following electron configurations is correct for oxygen (atomic number 8)?

1s2 2s2 2p2

1s2 2s2 2p3

1s2 2s2 2p4

1s2 2s2 2p5

The correct electron configuration for oxygen (atomic number 8) is '1s2 2s2 2p4'. Oxygen has 8 electrons, and following the Aufbau principle, we fill the lowest energy levels first, with the s orbital being filled before the p orbital. Each orbital can hold a maximum of 2 electrons, and thus, the p orbital will be filled with 4 electrons.

Explanation

The correct electron configuration for oxygen (atomic number 8) is '1s2 2s2 2p4'. Oxygen has 8 electrons, and following the Aufbau principle, we fill the lowest energy levels first, with the s orbital being filled before the p orbital. Each orbital can hold a maximum of 2 electrons, and thus, the p orbital will be filled with 4 electrons.

3. Which of the following statements is true regarding electron configuration?

Electrons fill orbitals from lower to higher energy levels.

Electrons fill orbitals from higher to lower energy levels.

Electrons fill orbitals randomly without following any particular order.

Electrons fill orbitals only when all higher energy levels are filled completely.

Electrons fill orbitals from lower to higher energy levels. This is known as the Aufbau principle and is based on the idea that electrons seek the most stable configuration by filling the lowest energy levels first.

Explanation

Electrons fill orbitals from lower to higher energy levels. This is known as the Aufbau principle and is based on the idea that electrons seek the most stable configuration by filling the lowest energy levels first.

4. Which electron configuration is correct for a neutral sulfur atom (atomic number 16)?

1s2 2s2 2p6 3s2 3p4

1s2 2s2 2p6 3s2 3p5

1s2 2s2 2p6 3s2 3p6

1s2 2s2 2p6 3s2 3p7

The correct electron configuration for a neutral sulfur atom (atomic number 16) is '1s2 2s2 2p6 3s2 3p4'. Sulfur has 16 electrons, and following the Aufbau principle, we fill the lowest energy levels first, with the s orbital being filled before the p orbital. The 3p orbital will be filled with 4 electrons.

Explanation

The correct electron configuration for a neutral sulfur atom (atomic number 16) is '1s2 2s2 2p6 3s2 3p4'. Sulfur has 16 electrons, and following the Aufbau principle, we fill the lowest energy levels first, with the s orbital being filled before the p orbital. The 3p orbital will be filled with 4 electrons.

5. What is Hund's rule?

Electrons will always occupy the lowest energy level available.

Electrons will pair up in the same orbital only when all orbitals have at least one electron.

Electrons will fill orbitals of the same energy level one at a time with parallel spins before pairing up.

Electrons will populate higher energy orbitals before filling lower energy orbitals.

Hund's rule states that electrons will fill orbitals of the same energy level one at a time with parallel spins before pairing up. This rule ensures the maximum spin alignment and therefore the maximum stability for the atom or ion.

Explanation

Hund's rule states that electrons will fill orbitals of the same energy level one at a time with parallel spins before pairing up. This rule ensures the maximum spin alignment and therefore the maximum stability for the atom or ion.

6. When writing electron configurations, which quantum number describes the shape of the orbital?

Principal quantum number (n)

Azimuthal quantum number (l)

Magnetic quantum number (m)

Spin quantum number (s)

The shape of the orbital is described by the azimuthal quantum number (l). It determines the subshell (s, p, d, f) to which an orbital belongs. The value of l ranges from 0 to (n-1), where n is the principal quantum number.

Explanation

The shape of the orbital is described by the azimuthal quantum number (l). It determines the subshell (s, p, d, f) to which an orbital belongs. The value of l ranges from 0 to (n-1), where n is the principal quantum number.

7. Which principle explains the filling order of atomic orbitals?

Hund's rule

Pauli exclusion principle

Aufbau principle

Octet rule

The filling order of atomic orbitals is explained by the Aufbau principle. According to this principle, electrons fill the lowest energy levels first before moving to higher energy levels. This principle helps in determining the electron configuration of atoms and their stability.

Explanation

The filling order of atomic orbitals is explained by the Aufbau principle. According to this principle, electrons fill the lowest energy levels first before moving to higher energy levels. This principle helps in determining the electron configuration of atoms and their stability.

8. Which of the following electron configurations violates the Pauli exclusion principle?

1s1

1s2

2s2 2p6

2s2 2p5

The electron configuration '2s2 2p5' violates the Pauli exclusion principle. This principle states that no two electrons in an atom can have the same four quantum numbers, meaning they must have opposite spins. In this configuration, two electrons are paired up with the same spin in the 2p orbital, violating the principle.

Explanation

The electron configuration '2s2 2p5' violates the Pauli exclusion principle. This principle states that no two electrons in an atom can have the same four quantum numbers, meaning they must have opposite spins. In this configuration, two electrons are paired up with the same spin in the 2p orbital, violating the principle.

9. Which electron configuration violates Hund's rule?

1s2 2s2 2p6

1s2 2s2 2p5

1s2 2s2 2p4

1s2 2s2 2p3

Electron configuration '1s2 2s2 2p5' violates Hund's rule because it pairs up electrons in the same orbital (2p) without filling all the orbitals with parallel spins first.

Explanation

Electron configuration '1s2 2s2 2p5' violates Hund's rule because it pairs up electrons in the same orbital (2p) without filling all the orbitals with parallel spins first.

10. Which electron configuration exists for an atom in an excited state?

1s2 2s2 2p6 3s1

1s2 2s2 2p6 3s2

1s2 2s2 2p6 3s2 3p1

1s2 2s2 2p6 3s2 3p2

The electron configuration '1s2 2s2 2p6 3s2 3p2' represents an atom in an excited state. An excited state occurs when an electron has absorbed energy and moved to a higher energy level or a higher energy orbital within the same level. In this case, the atom has one electron in the 3p orbital, which is higher in energy compared to the 3s orbitals.

Explanation

The electron configuration '1s2 2s2 2p6 3s2 3p2' represents an atom in an excited state. An excited state occurs when an electron has absorbed energy and moved to a higher energy level or a higher energy orbital within the same level. In this case, the atom has one electron in the 3p orbital, which is higher in energy compared to the 3s orbitals.