Science Atoms

Front 1

atom

Back 1

smallest particle into which an element can be divided

Front 2

theory

Back 2

unifying explanation for a broad hypotheses and observations that have been supported by testing

Front 3

electrons

Back 3

negatively charged particles in all atoms

found around the nucleus within the electron cloud

Front 4

model

Back 4

a representation of an object or system

Front 5

nucleus

Back 5

center of the atom-extremely dense positively charged

Front 6

electron clouds

Back 6

region inside an atom where electrons are likely to be found

Front 7

protons

Back 7

positively charged particles of the nucleus

Front 8

atomic mass unit (amu)

Back 8

SI unit used to express the masses of particles in atoms

each proton =mass of 1 amu
each neutron also given a mass of 1 amu

Front 9

neutrons

Back 9

particles of the nucleus that have no charge

Front 10

ion

Back 10

charged particle

Front 11

atomic number

Back 11

number of protons in the nucleus of an atom

Front 12

isotopes

Back 12

atoms that have same number of protons but different numbers of neutrons

Front 13

mass number

Back 13

is the sum of the protons and neutrons of an atom

Electrons are NOT included

Front 14

atomic mass

Back 14

is the weighted average of the masses of all the natually occurring isotopes of an element

Front 15

calc neutrons

Back 15

Mass number minus # of protons = # of neutrons

Front 16

atomic theory

Back 16

1) all substances are made from atoms: small particles that cannot be destroyed, created or divided.

2)Atoms of same element are exactly alike, different elements are different
3)Atoms join with other atoms to make new substances