6
C) atoms of the same element combine to form compounds.
D) all matter is made up of tiny particles called electrons.
E) a compound can contain different numbers of atoms as long as it has the same kinds of atoms.
26) Which of the following descriptions of a subatomic particle is correct?
A) A proton has a positive charge and a mass of approximately 1 amu.
B) An electron has a negative charge and a mass of approximately 1 amu.
C) A neutron has no charge and its mass is negligible.
D) A proton has a positive charge and a negligible mass.
E) A neutron has a positive charge and a mass of approximately 1 amu.
27) In an atom, the nucleus contains
A) an equal number of protons and electrons.
B) all the protons and neutrons.
C) all the protons and electrons.
D) only neutrons.
E) only protons.
28) The atomic number of an atom is equal to the number of
A) nuclei.
B) neutrons.
C) neutrons plus protons.
D) electrons plus protons.
E) protons.
29) The number of neutrons in an atom is equal to
A) the atomic number.
B) the mass number.
C) the mass number + the atomic number.
D) the mass number – the atomic number.
E) the number of protons.
30) The mass number of an atom can be calculated from
A) the number of electrons.
B) the number of protons plus neutrons.
C) the number of protons.