CHEMISTRY SEMESTER B PRACTICE SOLUTION
2026 COMPLETE QUESTIONS VERIFIED
RESPONSES
◉ What distinguishes 1 isotope of an element from another?
Answer: The number of neutrons affects the mass which creates
various isotopes.
◉ Write the atomic symbol for the following atoms or ions:
a. a sulfur atom that has gained 2 electrons.
b. an atom with 11 protons and 10 electrons.
c. a calcium atom that has lost 2 electrons. Answer: a. S^2-
b. Na^+
c. Ca^2+
◉ Write the nuclear symbol and hyphen notation for the following:
a. an atom made up of 6 protons, 8 neutrons, and 6 electrons.
b. an atom mad up of 7 protons, 7 neutrons, and 7 electrons. Answer:
a. 14^6 C and carbon-14
b. 14^7 N and nitrogen-14
, ◉ In the quantum-mechanical model of the atom, what is an orbital?
Answer: An orbital is a region in space that electrons occupy. Each
orbital can hold up to 2 electrons. Orbitals vary in shape, size, and
energy.
◉ What are the 4 types of atomic orbitals? Answer: -S = sphere.
-P = peanut.
-D = double peanut.
-F = funky (quadruple peanut).
◉ Which element is represented by each of the following electron
configurations?
a. 1s^2 2s^2 2p^6 3s^2
b. 1s^2 2s^2 sp^6 3s^2 3p^6 4s^2 3d^9
c. [Kr] 5s^2 4d^1
d. [He] 2s^2 2p^3 Answer: a. Mg
b. Cu
c. Y
d. N
◉ Write the electron configuration and the shorthand electorn
configuration for the following atoms:
Na
2026 COMPLETE QUESTIONS VERIFIED
RESPONSES
◉ What distinguishes 1 isotope of an element from another?
Answer: The number of neutrons affects the mass which creates
various isotopes.
◉ Write the atomic symbol for the following atoms or ions:
a. a sulfur atom that has gained 2 electrons.
b. an atom with 11 protons and 10 electrons.
c. a calcium atom that has lost 2 electrons. Answer: a. S^2-
b. Na^+
c. Ca^2+
◉ Write the nuclear symbol and hyphen notation for the following:
a. an atom made up of 6 protons, 8 neutrons, and 6 electrons.
b. an atom mad up of 7 protons, 7 neutrons, and 7 electrons. Answer:
a. 14^6 C and carbon-14
b. 14^7 N and nitrogen-14
, ◉ In the quantum-mechanical model of the atom, what is an orbital?
Answer: An orbital is a region in space that electrons occupy. Each
orbital can hold up to 2 electrons. Orbitals vary in shape, size, and
energy.
◉ What are the 4 types of atomic orbitals? Answer: -S = sphere.
-P = peanut.
-D = double peanut.
-F = funky (quadruple peanut).
◉ Which element is represented by each of the following electron
configurations?
a. 1s^2 2s^2 2p^6 3s^2
b. 1s^2 2s^2 sp^6 3s^2 3p^6 4s^2 3d^9
c. [Kr] 5s^2 4d^1
d. [He] 2s^2 2p^3 Answer: a. Mg
b. Cu
c. Y
d. N
◉ Write the electron configuration and the shorthand electorn
configuration for the following atoms:
Na
