Question 1

Each atomic orbital is uniquely defined with: A) Its energy specified by quantum number n. B) Its shape specified by quantum numbers l and m_l. C) Its energy, shape and orientation in space specified by quantum numbers n, l and m_l.

Accepted Answer

Atomic orbitals are defined by three quantum numbers: n (principal quantum number), l (azimuthal or angular momentum quantum number), and m_l (magnetic quantum number). The principal quantum number, n, determines the energy level and size of the orbital. The azimuthal quantum number, l, determines the shape of the orbital. The magnetic quantum number, m_l, determines the orientation of the orbital in space. Therefore, all three quantum numbers together specify an orbital's energy, shape, and orientation.

Question 2

Which combination of quantum numbers is not allowed? A) n = 3, l = -2, m_l = 2. B) n = 4, l = 0, m_l = 0. C) n = 3, l = 1, m_l = -1.

Accepted Answer

The quantum number $l$ (azimuthal or angular momentum quantum number) must be in the range of $0$ to $n-1$, where $n$ is the principal quantum number. Therefore, $l$ cannot be negative, making option A incorrect.

Question 3

The 5d subshell is defined with A) quantum numbers n = 5, l = 2 and four nodes in total B) quantum numbers n = 5, m_l = 2 and four nodes in total C) quantum numbers n = 5, l = 2 and five nodes in total

Accepted Answer

The 5d subshell is defined by the principal quantum number n = 5 and the azimuthal quantum number l = 2. The total number of nodes is given by n - 1, which is 4 for n = 5.

Question 4

The Pauli exclusion principle tells us that: A) One orbital can accommodate a maximum of two electrons with opposite signs of quantum number m_l. B) One orbital can accommodate a maximum of two electrons with opposite signs of quantum number m_s. C) One orbital can accommodate a maximum of two electrons with opposite signs of quantum number s.

Accepted Answer

The Pauli exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers. In an orbital, two electrons can coexist only if they have opposite spins, which is represented by the quantum number m_s.

Question 5

Chemical elements are organized in Mendeleev's periodic table. Within the table:
A) each block indicates the shell being filled
B) elements in the same period have the same core shell electronic configuration
C) each group corresponds to the completion of one subshell.

Accepted Answer

The answer of Chemical elements are organized in Mendeleev's periodic...

Question 6

As a general trend: A) atomic radii decrease from left to right in a period because Z_eff is increasing in the same direction. B) atomic radii decrease from left to right in a period because Z_eff is decreasing in the same direction. C) atomic radii increase from left to right in a period because Z_eff is increasing in the same direction

Accepted Answer

Atomic radii decrease from left to right in a period because the effective nuclear charge (Z_eff) is increasing in the same direction, pulling electrons closer to the nucleus and reducing the size of the atom.

Question 7

Which of the following correctly defines the first ionization energy: A) A(s) → A⁺(s) + e^-(g); I₁ = E(A⁺, s) - E(A, s) B) A(g) → A⁺(g) + e^-(g); I₁ = E(A, g) - E(A⁺, g) C) A(g) → A⁺(g) + e^-(g); I₁ = E(A⁺, g) - E(A, g).

Accepted Answer

First ionization energy is defined as the energy required to remove the most loosely bound electron from a neutral atom in the gaseous state to form a cation and an electron, both in the gaseous state. The correct expression is the energy of the ionized atom plus electron subtracted from the energy of the neutral atom, indicating the energy input required for the process.

Question 8

The first ionization energy, generally: A) is inversely proportional to the square of Z_eff and increases from left to right in the period. B) is directly proportional to the square of Z_eff and increases from left to right in the period C) is directly proportional to the square of Z_eff and increases from down a group.

Accepted Answer

The first ionization energy is directly proportional to the effective nuclear charge ($Z_{\text{eff}}^2$) because as the effective nuclear charge increases, it becomes more difficult to remove an electron due to the stronger attraction between the nucleus and the electron. Additionally, the first ionization energy generally increases from left to right across a period due to the increase in nuclear charge with the addition of protons, leading to a stronger attraction to electrons and thus higher ionization energy.

Question 9

Atoms of very electronegative elements:
A) have a tendency to attract shared electrons and are found in upper right corner of the periodic table
B) are metallic elements and are found on the left-hand side of the periodic table
C) have a tendency to attract electrons and are found in the upper left corner of the periodic table.

Accepted Answer

Electronegative elements have a strong tendency to attract shared electrons towards themselves and are indeed found in the upper right corner of the periodic table, excluding the noble gases. This is because electronegativity increases as you move from left to right across a period and decreases as you move down a group.

Question 10

Which of the following statements about oxygen is correct: A) Oxygen belongs to the p block, has lower I₁ value than carbon, is less electronegative than fluorine. B) Oxygen is a main group element, is less electronegative than fluorine but more electronegative than nitrogen C) Oxygen is a main group element, its atomic radius is greater than atomic radius for fluorine and has core electron configuration of Ne.

Accepted Answer

Oxygen is a main group element, is less electronegative than fluorine but more electronegative than nitrogen.

Quiz 1: Atomic Structure

Each atomic orbital is uniquely defined with:

Which combination of quantum numbers is not allowed?

The 5d subshell is defined with

The Pauli exclusion principle tells us that:

Chemical elements are organized in Mendeleev's periodic table. Within the table:

As a general trend:

Which of the following correctly defines the first ionization energy:

The first ionization energy, generally:

Atoms of very electronegative elements:

Which of the following statements about oxygen is correct: