1.
The number of wave cycles that pass a given point perunit of time
Correct Answer
B. Frequency
Explanation
Frequency refers to the number of wave cycles that pass a given point per unit of time. It is a measure of how often a wave oscillates or repeats itself. In other words, it determines the rate at which the wave's energy is being transferred. The higher the frequency, the more wave cycles pass a point in a given time period, indicating a higher pitch or energy level. Therefore, frequency is the correct answer in this context.
2.
The SI unit of frequency
Correct Answer
C. Hertz
Explanation
The SI unit of frequency is hertz. Hertz is a measure of the number of cycles per second in a wave or oscillation. It is named after Heinrich Hertz, a German physicist who made significant contributions to the study of electromagnetism. The hertz is commonly used to measure the frequency of various phenomena, including sound waves, radio waves, and electrical signals. It is a fundamental unit in physics and is widely used in scientific and technological applications.
3.
Lines of colored light obtained by passing the lightemitted by an element through a prism
Correct Answer
C. Atomic emmission spectrum
Explanation
The correct answer is atomic emission spectrum. An atomic emission spectrum refers to the lines of colored light that are obtained when the light emitted by an element is passed through a prism. Each element has a unique emission spectrum, which is a result of the specific energy levels and transitions of electrons within the atom. By analyzing the atomic emission spectrum, scientists can identify the elements present in a sample. The other options, such as quantum of energy and Aufbau principle, do not directly relate to the phenomenon of obtaining lines of colored light through a prism.
4.
The region around an atomic nucleus where an electronis likely to be moving
Correct Answer
B. Energy level
Explanation
The term "energy level" refers to the specific energy states that an electron can occupy within an atom. These energy levels are quantized, meaning they can only have certain discrete values. The region around an atomic nucleus where an electron is likely to be moving corresponds to these energy levels. Electrons can transition between energy levels by either absorbing or emitting energy in the form of photons, which is the basis of atomic emission spectra. The frequency of the emitted or absorbed light is directly related to the energy difference between the initial and final energy levels.
5.
A range of colors seen when light passes through a prism
Correct Answer
A. Spectrum
Explanation
The correct answer is "spectrum." A spectrum refers to a range of colors that are observed when light passes through a prism. This phenomenon is known as dispersion, where the different wavelengths of light are separated and create a continuous band of colors. The spectrum can be seen in various contexts, such as in rainbows or in the emission or absorption of light by different elements.
6.
Electrons enter orbitals of lowest energy first.
Correct Answer
A. Aufbau principle
Explanation
The Aufbau principle states that electrons fill the lowest energy orbitals first before moving to higher energy levels. This principle is based on the idea that electrons are organized in shells around the nucleus, with each shell having a specific energy level. Electrons will occupy the lowest energy level available before moving to higher levels. This principle helps to explain the order in which electrons fill the orbitals and the arrangement of elements in the periodic table.
7.
A region outside the nucleus where there is highprobability of finding an electron
Correct Answer
C. Atomic orbital
Explanation
An atomic orbital refers to a region outside the nucleus where there is a high probability of finding an electron. This is because electrons exist in a cloud-like formation around the nucleus, and the atomic orbital represents the specific region where an electron is most likely to be found. The concept of atomic orbitals is fundamental in understanding the behavior and properties of atoms.
8.
The amount of energy required to move an electron from one energy level to the next higher one
Correct Answer
A. Quantum of energy
Explanation
The correct answer is "quantum of energy". A quantum of energy refers to the minimum amount of energy required to move an electron from one energy level to the next higher one. In the context of quantum mechanics, energy levels are discrete and electrons can only exist in specific energy states. The energy difference between these states is quantized, meaning it can only take on certain discrete values. This concept is fundamental to understanding the behavior of electrons in atoms and molecules.
9.
The distance between crests of waves
Correct Answer
A. Wavelength
Explanation
Wavelength refers to the distance between crests of waves. It is a measure of the length of one complete wave cycle, usually measured in meters. Wavelength determines the characteristics of a wave, such as its frequency and energy. It is an important concept in physics and is used to describe various types of waves, including electromagnetic waves and sound waves.
10.
The height of a wave from the origin to the crest
Correct Answer
C. Amplitude
Explanation
The correct answer is amplitude. Amplitude refers to the height of a wave from the origin to the crest. It represents the maximum displacement of a wave from its equilibrium position. In other words, it measures the intensity or strength of a wave. Amplitude is usually represented by the distance between the baseline and the peak of a wave. It is an important parameter in understanding the characteristics and behavior of waves in various fields such as physics, sound, and electromagnetic waves.
11.
The fourth principal energy level has
Correct Answer
B. 16 orbitals.
Explanation
The fourth principal energy level, also known as the n=4 energy level, can hold a maximum of 32 electrons. Each orbital can accommodate a maximum of 2 electrons, and since there are a total of 16 orbitals in the n=4 energy level, the maximum number of electrons it can hold is 16*2=32.
12.
If the electron configuration of an element is Is22s22p63s23p5, the element is
Correct Answer
C. Chlorine.
Explanation
The electron configuration provided, Is22s22p63s23p5, indicates that the element has 17 electrons. By referring to the periodic table, we can determine that chlorine is the only element with 17 electrons. Therefore, the correct answer is chlorine.
13.
The quantum mechanical model of the atom
Correct Answer
A. Is concerned with the probability of finding an electron in a certain position.
Explanation
The quantum mechanical model of the atom is concerned with the probability of finding an electron in a certain position. This means that instead of defining the exact path of an electron around the nucleus, the model focuses on the likelihood of finding the electron in different regions of space. This probabilistic nature of the model is a fundamental aspect of quantum mechanics and is supported by experimental evidence. It allows scientists to predict the behavior of electrons and understand their distribution in atoms.
14.
The electron configuration of calcium is
Correct Answer
D. 1s2 2s2 2p6 3s2 3p6 4s2
Explanation
The electron configuration of an atom represents the arrangement of electrons in its energy levels or orbitals. In the given options, the electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 is correct for calcium. This configuration follows the Aufbau principle, which states that electrons fill the lowest energy levels first before moving to higher energy levels. The numbers and letters in the configuration represent the energy level (n) and the type of orbital (s or p) where the electrons are located. Therefore, the correct answer is 1s2 2s2 2p6 3s2 3p6 4s2.
15.
The maximum number of electrons that can occupy the third principal energy level is
Correct Answer
A. 18.
Explanation
The third principal energy level can contain a maximum of 18 electrons. This is because the first energy level can hold a maximum of 2 electrons, the second energy level can hold a maximum of 8 electrons, and the third energy level can hold a maximum of 18 electrons. This is based on the formula 2n^2, where n represents the principal energy level. Therefore, the correct answer is 18.
16.
As the frequency of light increases, the wavelength
Correct Answer
C. Decreases.
Explanation
As the frequency of light increases, the wavelength decreases. This is because the speed of light remains constant in a given medium, so as the frequency increases (which represents the number of wave cycles per second), the wavelength must decrease to maintain the same speed. In other words, as the frequency increases, the distance between each wave crest (wavelength) becomes shorter.
17.
The formula 2n2 represents
Correct Answer
B. The maximum number of electrons that can occupy an energy level.
Explanation
The formula 2n^2 represents the maximum number of electrons that can occupy an energy level. This formula is derived from the principle that each energy level can hold a maximum of 2n^2 electrons, where n represents the principal quantum number. This means that the first energy level (n=1) can hold a maximum of 2 electrons, the second energy level (n=2) can hold a maximum of 8 electrons, the third energy level (n=3) can hold a maximum of 18 electrons, and so on. Therefore, the formula 2n^2 accurately represents the maximum number of electrons that can occupy an energy level.
18.
In order to occupy the same orbital, two electrons must have
Correct Answer
D. Opposite spin.
Explanation
Two electrons must have opposite spin in order to occupy the same orbital. This is based on the Pauli exclusion principle, which states that no two electrons in an atom can have the same set of quantum numbers. The spin quantum number is one of these quantum numbers, and it can have two possible values: +1/2 or -1/2. Therefore, in order for two electrons to occupy the same orbital, they must have opposite spin values, ensuring that their quantum numbers are different.
19.
Stable electron configurations are likely to contain
Correct Answer
D. Filled energy sublevels.
Explanation
Stable electron configurations are likely to contain filled energy sublevels because electrons naturally arrange themselves in the lowest energy states available. Filling the energy sublevels ensures that the electrons are in their most stable positions, minimizing their energy. Unfilled s orbitals and high-energy electrons are associated with instability, as they represent higher energy states. Having fewer electrons than unstable configurations does not necessarily indicate stability or instability, as stability is primarily determined by the arrangement of the electrons in the energy sublevels.
20.
According to Hund's rule, when electrons occupy orbitals of equal energy,
one electron enters each orbit until
Correct Answer
A. All the orbitals contain one electron, with spins parallel.
Explanation
According to Hund's rule, when electrons occupy orbitals of equal energy, they will first fill each orbital with one electron before pairing up. This means that all the orbitals will contain one electron, and the spins of these electrons will be parallel. This rule helps to explain the observed electron configurations of atoms and the stability of half-filled and fully-filled subshells.
21.
Identify the elements that have the following electron configurations. Is22s22p63s23pl
Correct Answer
B. Aluminum
Explanation
The electron configuration given, 2s22p63s23pl, corresponds to the electron configuration of aluminum. The "2s22p6" part indicates that there are 8 electrons in the second energy level (2s2 and 2p6), and the "3s23pl" part indicates that there are 3 electrons in the third energy level (3s2 and 3p1). This matches the electron configuration of aluminum, which has 13 electrons in total. Cobalt and krypton have different electron configurations, so they are not the correct answers.
22.
Identify the elements that have the following electron configurationsI^2s22p63s23p63dw4s24p6
Correct Answer
C. Krypton
Explanation
The given electron configuration, I^2s22p63s23p63dw4s24p6, represents the electron arrangement of the element krypton. Krypton is a noble gas located in the 18th group of the periodic table. It has a total of 36 electrons, with 2 in the 1s orbital, 2 in the 2s orbital, 6 in the 2p orbital, 2 in the 3s orbital, 6 in the 3p orbital, 10 in the 3d orbital, 2 in the 4s orbital, and 6 in the 4p orbital. Therefore, krypton is the element that matches the given electron configuration.
23.
Identify the elements that have the following electron configurations. Is22s22p63s23p63d74si
Correct Answer
C. Cobalt
Explanation
The given electron configuration, Is22s22p63s23p63d74si, corresponds to the element cobalt. This is because cobalt has 27 electrons, and the given configuration accounts for all 27 electrons. Aluminum has the electron configuration 1s22s22p63s23p1, which is different from the given configuration. Krypton has the electron configuration 1s22s22p63s23p64s23d104p6, which is also different from the given configuration. Therefore, the correct answer is cobalt.
24.
Consider the elements neon, bromine, and phosphorus. Which has three electrons in its 3p sublevel?
Correct Answer
A. pHospHorus
Explanation
Phosphorus has three electrons in its 3p sublevel because the 3p sublevel can hold a maximum of six electrons. Neon is a noble gas and has a completely filled 3p sublevel with zero electrons. Bromine has five electrons in its 3p sublevel. Therefore, phosphorus is the only element among the given options that has three electrons in its 3p sublevel.
25.
Consider the elements neon, bromine, and phosphorus. Which has its highest energy level completely filled?
Correct Answer
C. Neon
Explanation
Neon has its highest energy level completely filled. In the periodic table, elements are arranged in increasing order of atomic number. Neon is located in the second period and has an atomic number of 10. It has a completely filled second energy level with 8 electrons, which is the maximum number of electrons that can occupy that level. Bromine, on the other hand, is located in the fourth period and has an atomic number of 35, indicating that its highest energy level is not completely filled. Phosphorus, located in the third period with an atomic number of 15, also does not have its highest energy level completely filled. Therefore, neon is the correct answer.
26.
Consider the elements neon, bromine, and phosphorus. Which has
the highest occupied energy level?
Correct Answer
B. Bromine
Explanation
Bromine has the highest occupied energy level among neon, bromine, and phosphorus. This is because bromine has more electrons in its outermost energy level compared to neon and phosphorus. Neon has a completely filled outermost energy level, while phosphorus has an incomplete outermost energy level. Bromine, on the other hand, has one electron less than a completely filled outermost energy level, making it have the highest occupied energy level among the three elements.
27.
What is the maximum number of electrons that can occupy each of the first five principal energy levels?
Correct Answer
A. 25.Energy level 1 = 2
Energy level 2 = 8
Energy level 3 = 18
Energy level 4 = 32
Energy level 5 = 50
Explanation
The maximum number of electrons that can occupy each of the first five principal energy levels are as follows: Energy level 1 can hold a maximum of 2 electrons, energy level 2 can hold a maximum of 8 electrons, energy level 3 can hold a maximum of 18 electrons, energy level 4 can hold a maximum of 32 electrons, and energy level 5 can hold a maximum of 50 electrons.