Question :
1.What the three primary particles found in an atom?
A) : 1318363
1.What are the three primary particles found in an atom?
A) neutron, positron, and electron
B) electron, neutron, and proton
C) electron, proton, and nucleon
D) positron, electron, and nucleon
E) proton, electron, and neutrino
2.What is the value of the mass number in the isotope ?
A) 53
B) 78
C) 126.9
D) 131
E) 184
3.What term is used to describe atoms of the same element that have different masses?
A) radioactive
B) constituents
C) isotopes
D) telomers
E) isomers
4.Which statement explains why isotopes have different mass numbers?
A) Isotopes differ in the number of protons each contains.
B) Isotopes differ in the number of electrons each contains.
C) Isotopes differ in the number of neutrons each contains.
D) Isotopes differ in the number of protons and neutrons each contains.
E) Isotopes differ in the number of protons and electrons each contains.
5.When a neutral atom gains one or more electrons, what type of particle is formed?
A) an anion
B) an isotope
C) a proton
D) a positron
E) a cation
6.What is always true for a neutral atom?
A) there is an equal number of protons and neutrons
B) there is an equal number of protons and electrons
C) there is an equal number of protons, neutrons, and electrons
D) the number of protons and neutrons is an even number
E) the number of protons, neutrons, and electrons is an even number
7.What was J. J. Thomson’s important discovery about cathode rays in 1897?
A) Cathode rays were indestructible.
B) Cathode rays were heavier than anode rays.
C) Cathode rays consisted of a stream of electrons.
D) Cathode rays were produced by all radioactive atoms.
E) Cathode rays were able to initiate radioactive decay of an atom.
8.What is Rutherford’s important contribution to our knowledge of atomic structure?
A) Atoms contain a small, dense, positively charged nucleus, surrounded largely by empty space.
B) The atom cannot be created, divided, destroyed, or converted to any other type of atom.
C) Electrons in an atom have the magnetic property of spin.
D) Electrons are confined to certain specific regions of space outside the nucleus.
E) Electrons follow circular paths around the nucleus of an atom.
9.Which statement concerning atoms is FALSE?
A) The atomic number of an atom is the number of protons it contains.
B) The mass number of an atom is the sum of the number of protons, neutrons, and electrons it contains.
C) The nucleus of an atom contains its protons and neutrons, and is positively charged.
D) The nucleus of an atom is the heaviest part of the atom.
E) Electrons reside outside the nucleus in what is called the electron cloud.
10.Which describes the basic concept of Bohr’s theory of the atom?
A) Atoms contain a small, dense positively charged region called the nucleus.
B) The energy of an electron in an atom is quantized; it has only certain allowable values.
C) Light is made up of particles called photons.
D) Electrons have the magnetic property of spin.
E) Radioactive atoms spontaneously decay and release large amounts of energy from the nucleus.
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