Star-atomic And Molecular Structure
- 1.
Which of the following ordered pairs of elements shows an increase in atomic number but a decrease in average atomic mass?
- A.
Ag to Pd
- B.
Co to Ni
- C.
Cr to Mo
- D.
Ge to Sn
Correct Answer
B. Co to NiExplanation
The ordered pair of elements Co to Ni shows an increase in atomic number but a decrease in average atomic mass. This is because as you move from cobalt (Co) to nickel (Ni) in the periodic table, the atomic number increases by 1, indicating an increase in the number of protons in the nucleus. However, the average atomic mass decreases because the atomic mass of nickel is slightly lower than that of cobalt.Rate this question:
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- 2.
Why is cobalt (Co) placed before nickel (Ni) on the periodic table of the elements even though it has a higher average atomic mass than nickel?
- A.
Nickel has fewer electrons.
- B.
Cobalt was discovered first
- C.
Nickel has one more proton
- D.
Cobalt has a lower density.
Correct Answer
C. Nickel has one more protonExplanation
Cobalt (Co) is placed before nickel (Ni) on the periodic table because it has a lower atomic number. The atomic number is determined by the number of protons in an atom's nucleus. Even though cobalt has a higher average atomic mass than nickel, atomic number takes precedence in determining the placement on the periodic table. Therefore, nickel, with one more proton than cobalt, is placed after cobalt.Rate this question:
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- 3.
Generally, how do atomic masses vary throughout the periodic table of the elements?
- A.
They increase from right to left and bottom to top.
- B.
They increase from left to right and top to bottom.
- C.
They increase from right to left and top to bottom.
- D.
They increase from left to right and bottom to top.
Correct Answer
B. They increase from left to right and top to bottom.Explanation
Atomic masses generally increase from left to right and top to bottom in the periodic table of elements. This is because as you move from left to right across a period, the number of protons in the nucleus increases, resulting in a greater positive charge and stronger attraction for electrons. This increased attraction leads to a smaller atomic radius and higher atomic mass. Similarly, as you move down a group, the number of energy levels or shells increases, causing the atomic radius to increase and atomic mass to increase as well.Rate this question:
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- 4.
.Iodine would have chemical properties most like
- A.
Tellurium (Te).
- B.
Chlorine (Cl).
- C.
Manganese (Mn).
- D.
Xenon (Xe).
Correct Answer
B. Chlorine (Cl).Explanation
Iodine would have chemical properties most like chlorine (Cl) because they both belong to the same group in the periodic table, Group 17 or the halogens. Halogens share similar chemical properties due to their similar electron configurations and tendency to gain one electron to achieve a stable octet. Therefore, iodine and chlorine would exhibit similar reactivity and behavior in chemical reactions.Rate this question:
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- 5.
Which of the following elements is classified as a metal?
- A.
Bromine
- B.
Helium
- C.
Sulfur
- D.
Lithium
Correct Answer
D. LithiumExplanation
Lithium is classified as a metal because it is located in the alkali metal group on the periodic table. Metals are typically found on the left side of the periodic table and have characteristics such as being shiny, malleable, and good conductors of electricity. Lithium exhibits these properties, making it a metal.Rate this question:
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- 6.
The chart below shows the relationship between the first ionization energy and the increase in atomic number. The letter on the chart for the alkali family of elements is
- A.
W
- B.
X
- C.
Y
- D.
Z
Correct Answer
A. WExplanation
The alkali family of elements refers to the group of elements in Group 1 of the periodic table, which includes elements such as lithium, sodium, and potassium. The first ionization energy is the energy required to remove the outermost electron from an atom. Looking at the chart, it can be observed that the first ionization energy decreases as the atomic number increases for the alkali family of elements. Therefore, the correct letter on the chart for the alkali family of elements is W.Rate this question:
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- 7.
Which of the following atoms has the largest atomic radius?
- A.
Barium (Ba)
- B.
Chlorine (Cl)
- C.
Iodine (I)
- D.
Magnesium (Mg)
Correct Answer
A. Barium (Ba)Explanation
Barium (Ba) has the largest atomic radius among the given atoms. Atomic radius is the distance between the nucleus and the outermost shell of an atom. As you move down a group in the periodic table, the atomic radius increases due to the addition of more electron shells. Barium is located at the bottom of Group 2, while the other atoms are in Group 17. Therefore, Barium has more electron shells compared to the other atoms, resulting in a larger atomic radius.Rate this question:
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- 8.
Which of the following atoms has six valence electrons?
- A.
Argon (Ar)
- B.
Magnesium (Mg)
- C.
Sulfur (S)
- D.
Silicon (Si)
Correct Answer
C. Sulfur (S)Explanation
Sulfur (S) has six valence electrons. The valence electrons are the electrons in the outermost energy level of an atom, and sulfur is in Group 16 of the periodic table. Group 16 elements, also known as the oxygen family, have six valence electrons. Therefore, sulfur has six valence electrons.Rate this question:
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- 9.
Which statement bestdescribes the density of an atom’s nucleus?
- A.
The nucleus occupies very little of the atom’s volume and contains little of its mass.
- B.
The nucleus occupies very little of the atom’s volume but contains most of its mass.
- C.
The nucleus occupies most of the atom’s volume and contains most of its mass.
- D.
The nucleus occupies most of the atom’s volume but contains little of its mass.
Correct Answer
B. The nucleus occupies very little of the atom’s volume but contains most of its mass.Explanation
The correct answer is that the nucleus occupies very little of the atom's volume but contains most of its mass. This is because the nucleus is the central part of the atom, where most of its mass is concentrated. It is made up of protons and neutrons, which are much larger and heavier than the electrons that occupy the outer regions of the atom. Therefore, even though the nucleus is very small compared to the overall size of the atom, it contains the majority of its mass.Rate this question:
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- 10.
What information do the experimental results reveal about the nucleus of the gold atom?
- A.
The nucleus is small and is the densest part of the atom.
- B.
The nucleus contains less than half the mass of the atom.
- C.
The nucleus contains small positive and negative particles.
- D.
The nucleus is large and occupies most of the atom’s space.
Correct Answer
A. The nucleus is small and is the densest part of the atom.Explanation
The experimental results suggest that the nucleus of the gold atom is small and dense.Rate this question:
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- 11.
Why are enormous amounts of energy required to separate a nucleus into its component protons and neutrons even though the protons in the nucleus repel each other?
- A.
The force of the protons repelling each other is small compared to the attraction of the neutrons to each other.
- B.
The electrostatic forces acting between other atoms lowers the force of repulsion of the protons.
- C.
The interactions between neutrons and electrons neutralize the repulsive forces between the protons.
- D.
The forces holding the nucleus together are much stronger than the repulsion between the protons.
Correct Answer
D. The forces holding the nucleus together are much stronger than the repulsion between the protons.Explanation
The forces holding the nucleus together are much stronger than the repulsion between the protons. This means that the attractive forces between the protons and neutrons in the nucleus are much greater than the repulsive forces between the protons. As a result, a significant amount of energy is required to overcome these strong attractive forces in order to separate the nucleus into its component protons and neutrons.Rate this question:
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- 12.
The most abundant isotope of lead contains 82 protons and 124 neutrons packed closely together in the nucleus. Why do the protons stay together in the nucleus rather than fly apart?
- A.
Electrons in neighboring atoms neutralize repulsive forces between protons
- B.
Neutrons effectively block the protons and keep them far apart to prevent repulsion
- C.
Electrostatic forces between neutrons and protons hold the nucleus together
- D.
Nuclear forces overcome repulsive forces between protons in the nucleus
Correct Answer
D. Nuclear forces overcome repulsive forces between protons in the nucleusExplanation
The correct answer is that nuclear forces overcome repulsive forces between protons in the nucleus. These nuclear forces, also known as strong nuclear forces, are responsible for holding the nucleus together. They are much stronger than the electrostatic repulsion between protons, which would normally cause them to fly apart. The nuclear forces act over very short distances, effectively counteracting the repulsive forces and keeping the protons tightly packed together in the nucleus.Rate this question:
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- 13.
Which equation correctly represents the alpha decay of polonium-214? A. B. C. D.
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
C. C -
- 14.
A 2-cm-thick piece of cardboard placed over a radiation source would be most effective in protecting against which type of radiation?
- A.
Alpha
- B.
Beta
- C.
Gamma
- D.
X-ray
Correct Answer
A. AlpHaExplanation
A 2-cm-thick piece of cardboard would be most effective in protecting against alpha radiation. Alpha particles are relatively large and heavy, consisting of two protons and two neutrons. They have a low penetration power and can be easily stopped by a few centimeters of air or a thin barrier such as cardboard. On the other hand, beta, gamma, and x-ray radiation have higher penetration powers and would require thicker or denser shielding materials to effectively block them.Rate this question:
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Mar 21, 2023Quiz Edited by
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Mar 29, 2011Quiz Created by
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