click below
click below
Normal Size Small Size show me how
Chpt. 11 SCI Vocab.
paes chapter 11 science vocabulary
Term | Definition |
---|---|
atom | the smallest unit of an element that maintains the properties of that element |
electron | a subatomic particle that has a negative charge |
nucleus | an atom's central region, which is made up of protons and neutrons |
electron cloud | a region around the nucleus of an atom where electrons are likely to be found |
proton | a subatomic particle that has a positive charge and that is located in the nucleus of an atom; the number of protons in the nucleus is the atomic number, which determines the identity of an element |
atomic mass unit (AMU) | a unit of mass that describes the mass of an atom or molecule |
neutron | a subatomic particle that has no charge and that is found in the nucleus of an atom |
atomic number | the number of protons in the nucleus of an atom the same for all atoms of an element |
isotope | an atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass) |
mass number | the sum of the numbers of protons and neutrons in the nucleus of an atom |
atomic mass | the mass of an atom expressed in atomic mass units |