4.2 Flashcards
1
Q
a positively charge particles in the neucleus
A
proton
2
Q
a unit of a mass that describes the mass of an atom or molecule
A
atomic mass unit
3
Q
particles of the nucleus that have no electrical charge
A
neutron
4
Q
The number of protons in the nucleus of an atom
A
atomic number
5
Q
an atom that has the same number of protons as the other atoms of the same element do but has a different number of neutrons
A
isotope
6
Q
the sum of the numbers of protons and neutrons in the nucleus of an atom
A
mass number
7
Q
the mass of an atom expressed in the atomic mass units
A
atomic mass
