8th Grade The Atom

total number of proton and neutrons in an atom’s nucleus

positively charged particles

contain negatively charged particles

atoms of the same element that have different numbers of neutrons

a small, dense center that has a positive charge

atomic theory suggested a model in which electrons move around the nucleus in circular path

electrons that move within an area around the nucleus

discovered that the nucleus contains unchanged particles called neutrons

suggested atoms have a nucleus, which is a small dense center with a positive charge

is the smallest particle into which an element can be divided and still be the same element.

number of protons in the nucleus of an atom

uncharged particles

provided evidence that atoms contain negatively charged particles called electrons

stated that all matter is made up of atoms that cannot be created, divided or destroyed