Science chap 7

the smallest piece of an element that still represents an element

a particle with one negative charge (-1)

most of an atom’s mass and positive charge is concentrated in a small area in the center of an atom

atomic particle that has one positive charge (1+)

neutron

area around an atomic nucleus where an electron is most likely to be located

number of protons in an atom of an element

element is the avarage mass of the element isotopes, weighted according to the abundance at each isotope

element that spontaneously emits radiation

process that occurs when an unstable atomic nucleus changes into another more stable nucleus ny emitting radiation

ion

Two neutral atoms that have the ame atomic number and different mass numbers are

An ion that has a negative charge is formed when an atom

The atomic theories of Dalton and Democritus included the idea that atoms

Two atoms of different elements will definitely have different numbers of

what always have a positive or negative charge

An elements blank and the number of protons in the nucleus of its atoms are always the same

The-blank is determined adding the number of protons and neutrons in an atom

Based on his research on the atom chadwick concluded that

Atoms of the same element that have different numbers of neutrons