Introduction To The Atom
- 1.
In the original Greek, the word "atom" means
- A.
Uncuttable
- B.
Rotational
- C.
Systematic
- D.
Origin
Correct Answer
A. UncuttableExplanation
The word "atom" originates from the original Greek term meaning "uncuttable." This suggests that the concept of an atom was initially believed to be the smallest, indivisible unit of matter. The term "uncuttable" implies that atoms cannot be further divided or broken down into smaller components. This understanding of atoms as fundamental building blocks of matter forms the basis of atomic theory in chemistry and physics.Rate this question:
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- 2.
The positively-charged subatomic particle is a
- A.
Neutron
- B.
Graviton
- C.
Proton
- D.
Electron
Correct Answer
C. ProtonExplanation
A positively-charged subatomic particle refers to a particle that carries a positive charge. Among the given options, the only particle that fits this description is the proton. Protons are found in the nucleus of an atom and have a positive charge. Neutrons have no charge, electrons have a negative charge, and gravitons are theoretical particles that have not been observed. Therefore, the correct answer is proton.Rate this question:
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- 3.
An electron is a
- A.
Negatively-charged subatomic particle
- B.
Semiconductor electrical substrate
- C.
Packet of light energy emitted by atoms
- D.
Electroweak interaction with material forces
Correct Answer
A. Negatively-charged subatomic particleExplanation
An electron is a negatively-charged subatomic particle. This means that it carries a negative charge and is one of the fundamental particles that make up atoms. Electrons orbit around the nucleus of an atom and are involved in various chemical and electrical interactions. They play a crucial role in determining the properties and behavior of matter.Rate this question:
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- 4.
You can not know both an electron's ___________ and ____________ at any point in time.
- A.
Size, shape
- B.
Location, momentum
- C.
Spin, vibration
- D.
Charge, velocity
Correct Answer
B. Location, momentumExplanation
According to the Heisenberg uncertainty principle, it is impossible to simultaneously know the exact position (location) and momentum of an electron. This principle states that the more precisely one property is known, the less precisely the other can be known. Therefore, it is not possible to determine both the location and momentum of an electron at any given point in time.Rate this question:
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- 5.
What is an orbital?
- A.
Quantum mechanic shifts an electron makes when an atom absorbs energy
- B.
Chemical reaction between an electron and a proton
- C.
Spinning path the electron particle makes around the nucleus
- D.
Mathematical probability function of where an electron is likely to be
Correct Answer
D. Mathematical probability function of where an electron is likely to beExplanation
An orbital refers to a mathematical probability function that describes the likelihood of finding an electron in a particular region around the nucleus of an atom. It does not represent the actual path or trajectory of the electron, but rather the probability of locating the electron in a specific space. This concept is a fundamental aspect of quantum mechanics and helps to understand the behavior and properties of atoms and molecules.Rate this question:
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- 6.
One atomic mass unit equals
- A.
The mass of an atom in a vacuum at zero degrees kelvin
- B.
The mass of 1 proton or 1 neutron
- C.
A unit to compare relative atomic masses
- D.
The weight of an atom in a vacuum
Correct Answer
B. The mass of 1 proton or 1 neutronExplanation
One atomic mass unit equals the mass of 1 proton or 1 neutron. Protons and neutrons are the subatomic particles found in the nucleus of an atom. They have approximately the same mass, which is why one atomic mass unit is defined as the mass of either a proton or a neutron. This unit is used to compare the masses of different atoms and is essential in understanding the concept of relative atomic masses.Rate this question:
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- 7.
What is the negatively-charged subatomic particle?
- A.
Neutron
- B.
Graviton
- C.
Proton
- D.
Electron
Correct Answer
D. ElectronExplanation
The negatively-charged subatomic particle is the electron. Electrons are found in the electron cloud surrounding the nucleus of an atom and they carry a negative charge. They are one of the fundamental particles that make up atoms and play a crucial role in chemical reactions and electrical conductivity.Rate this question:
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- 8.
What is the uncharged subatomic particle?
- A.
Neutron
- B.
Graviton
- C.
Proton
- D.
Electron
Correct Answer
A. NeutronExplanation
A neutron is an uncharged subatomic particle found in the nucleus of an atom. Unlike protons and electrons, which carry positive and negative charges respectively, neutrons have no electrical charge. This makes them neutral and allows them to play a crucial role in stabilizing the nucleus of an atom. Neutrons are responsible for holding the protons together through the strong nuclear force, preventing them from repelling each other due to their positive charges. Therefore, the correct answer for the uncharged subatomic particle is neutron.Rate this question:
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- 9.
An electron gains potential energy as it
- A.
Accumulates charge in response to the protons in the nucleus
- B.
Moves away from the nucleus
- C.
Interacts with gravitational fields
- D.
Increases its radioactive decay
Correct Answer
B. Moves away from the nucleusExplanation
As an electron moves away from the nucleus, it gains potential energy. This is because the electron and the positively charged protons in the nucleus are attracted to each other by the electromagnetic force. As the distance between the electron and the nucleus increases, the force of attraction decreases, resulting in an increase in potential energy for the electron. Therefore, the correct answer is that an electron gains potential energy as it moves away from the nucleus.Rate this question:
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- 10.
I know what element an atom is by the
- A.
Number of protons in the nucleus
- B.
Atomic radius, in angstroms
- C.
Number of neutrons in the nucleus
- D.
String vibrations the atom emits when excited
Correct Answer
A. Number of protons in the nucleusExplanation
The number of protons in the nucleus of an atom determines the element it is. This is because each element has a unique number of protons, known as its atomic number. The atomic number defines the identity of the element and determines its chemical properties. Therefore, by knowing the number of protons in the nucleus, one can identify the element to which the atom belongs.Rate this question:
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- 11.
An element's atomic number is
- A.
The quantity of subatomic particles in the nucleus
- B.
The number of protons
- C.
The number of electrons
- D.
The number of electron orbitals surrounding a nucleus
Correct Answer
B. The number of protonsExplanation
An element's atomic number is the number of protons in its nucleus. Protons are positively charged subatomic particles found in the nucleus of an atom. The atomic number determines the identity of the element and its position in the periodic table. It also determines the number of electrons in a neutral atom, as in a neutral atom the number of protons is equal to the number of electrons. Therefore, the correct answer is the number of protons.Rate this question:
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- 12.
An atom has a neutral charge if
- A.
The nucleus consists of neutrons
- B.
Protons repel electrons because they have different charges
- C.
Quantized spin dynamics alter orbital strengths
- D.
The number of protons equals the number of electrons
Correct Answer
D. The number of protons equals the number of electronsExplanation
An atom has a neutral charge when the number of protons, which carry a positive charge, is equal to the number of electrons, which carry a negative charge. This balance of positive and negative charges cancels out, resulting in a neutral overall charge for the atom.Rate this question:
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- 13.
The mass of one proton equals the masses of about
- A.
20 neutrons
- B.
2,000 electrons
- C.
20,000 electrons
- D.
100,000 neutrons
Correct Answer
B. 2,000 electronsExplanation
The mass of one proton is much larger than the mass of one electron. Therefore, in order for the mass of one proton to equal the mass of 2,000 electrons, each electron would have to be significantly smaller in mass compared to a proton. This explanation is consistent with the given answer choice.Rate this question:
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- 14.
The atomic weight of an element is the
- A.
Weighted mass of the most common isotope of that element
- B.
Weighted average of the masses of naturally-occurring isotopes
- C.
Largest weight of an isotope of that element
- D.
Relative weight percent of one atom to others in a compound
Correct Answer
B. Weighted average of the masses of naturally-occurring isotopesExplanation
The atomic weight of an element is the weighted average of the masses of naturally-occurring isotopes. This means that it takes into account the abundance of each isotope in nature and calculates a weighted average based on those abundances. Isotopes with higher abundances contribute more to the overall atomic weight, while isotopes with lower abundances have less impact. This is important because it reflects the actual distribution of isotopes in nature and provides a more accurate representation of the element's atomic weight.Rate this question:
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- 15.
Isotopes are
- A.
Chemical compounds with the same states of electrons
- B.
Atoms with the same number of neutrons but a different number of protons
- C.
Atoms with the same number of protons but a different number of neutrons
- D.
Chemical compounds with distinct electron orbitals
Correct Answer
C. Atoms with the same number of protons but a different number of neutronsExplanation
Isotopes are atoms with the same number of protons but a different number of neutrons. This means that isotopes have the same atomic number (which is determined by the number of protons) but different atomic masses (which is determined by the number of protons and neutrons combined). Isotopes of an element have similar chemical properties since they have the same number of protons and electrons, but they may have different physical properties due to their different atomic masses.Rate this question:
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- 16.
What percent of matter is made of free space, at an atomic level?
- A.
67.33%
- B.
0.01%
- C.
99.99%
- D.
23.67%
Correct Answer
C. 99.99%Explanation
At an atomic level, matter is mostly made up of empty space. This is because atoms consist of a nucleus surrounded by electrons, and the size of the nucleus is much smaller compared to the space occupied by the electrons. Therefore, almost all of the space within an atom is empty. The correct answer, 99.99%, reflects this fact and indicates that only a tiny fraction of matter is actually occupied by particles, while the majority is empty space.Rate this question:
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Mar 21, 2023Quiz Edited by
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