1.
It is important to learn about quantum mechanics because
Correct Answer
B. This information tells us why certain elements may be very reactive while others may be relatively non-reactive.
Explanation
Learning about quantum mechanics is important because it provides an understanding of why certain elements may be very reactive while others may be relatively non-reactive. Quantum mechanics explains the behavior and interactions of atoms and molecules at the microscopic level, including the arrangement and movement of electrons. This knowledge helps to explain the varying reactivity of different elements based on their electron configurations and the stability of their outer electron shells.
2.
The first quantum number is known as the _________quantum number and says that ________________________.
Correct Answer
C. Principle quantum number; electrons are found in layers around the nucleus of the atom.
Explanation
The first quantum number is known as the principle quantum number and it describes the energy level or shell in which an electron is located. It indicates the distance of the electron from the nucleus and the size of the electron cloud. Electrons are found in layers or orbitals around the nucleus of the atom, with each orbital capable of holding a specific number of electrons.
3.
How many layers of electrons might one encounter in an atom according to the theory of quantum mechanincs?
Correct Answer
C. 7
Explanation
According to the theory of quantum mechanics, an atom consists of multiple energy levels or shells. Each shell can hold a specific number of electrons. The maximum number of electrons that can be found in an atom is determined by the formula 2n^2, where n is the number of the energy level or shell. Therefore, the correct answer is 7, as the seventh energy level or shell can hold a maximum of 2(7)^2 = 98 electrons.
4.
The orbital quantum number says that
Correct Answer
D. Electrons travel in pathways having four different shapes.
Explanation
The orbital quantum number describes the shape of the electron's pathway or orbital around the nucleus of an atom. This means that electrons can be found in four different shaped pathways, known as s, p, d, and f orbitals. The orbital quantum number does not refer to the layers around the nucleus or the spinning motion of electrons.
5.
When thinking about the different shaped paths on which electrons travel, which shape below is not one of the shapes we discussed?
Correct Answer
A. Rectilinear
Explanation
The question asks for the shape that is not discussed when considering the different shaped paths of electrons. The shapes mentioned in the question are spherical, pear-shaped, and dumb-bell shaped. The term "rectilinear" refers to a path or line that is straight, without any curves or angles. Since the question asks for a shape, and rectilinear is not a shape but rather a description of a path, it is the correct answer.
6.
The magnetic quantum number says
Correct Answer
D. That the p-shaped orbits are found in three different orientations in space (x, y, z)
Explanation
The magnetic quantum number determines the orientation of the p-shaped orbitals in space. It specifies the three possible orientations of the p orbitals along the x, y, and z axes. These orientations are represented by the values -1, 0, and +1 respectively. Therefore, the correct answer is "That the p-shaped orbits are found in three different orientations in space (x, y, z)".
7.
The Spin quantum number says
Correct Answer
A. That the electrons travel in pairs with one electron spinning clockwise and the second spinning counterclockwise.
Explanation
The spin quantum number states that electrons exist in pairs with opposite spins, where one electron spins clockwise and the other spins counterclockwise. This concept is based on experimental observations and is a fundamental property of electrons in atoms. The spin of an electron is not related to its motion or position, but rather represents an intrinsic property of the particle. The pairing of electrons with opposite spins is important for understanding the behavior of electrons in chemical bonding and the stability of atoms.
8.
Choose the element symbol pair which is correctly matched.
Correct Answer
D. Cobalt Co
Explanation
The correct answer is Cobalt (Co). Cobalt is a transition metal and its symbol is Co. Carbon is represented by the symbol C, Calcium by Ca, and Chlorine by Cl. Therefore, the element symbol pair that is correctly matched is Cobalt - Co.
9.
The atomic number of an element tells the
Correct Answer
C. Number of protons, neutrons, and electrons found in an atom of that element.
Explanation
The atomic number of an element tells the number of protons, neutrons, and electrons found in an atom of that element. This is because the atomic number represents the number of protons in the nucleus of an atom, and in a neutral atom, the number of protons is equal to the number of electrons. Neutrons are also found in the nucleus, but their number is not determined by the atomic number. Therefore, the correct answer is that the atomic number tells the number of protons, neutrons, and electrons found in an atom of that element.
10.
Of the three subatomic particles, electrons have the greatest mass.
Correct Answer
B. False
Explanation
The statement is false because electrons have the smallest mass among the three subatomic particles. Protons and neutrons have much greater mass compared to electrons.