Unit 2 test

Unit 2

Democritus

Greek philosopher who proposed the concept of atoms

Dalton

English chemist who developed the atomic theory

Rutherford

Physicist who discovered the nucleus and proposed the nuclear model of the atom

Thomson

Physicist who discovered the electron and proposed the plum pudding model of the atom

Bohr

Physicist who developed the planetary model of the atom

nucleus

Central part of an atom that contains protons and neutrons

protons

Positively charged subatomic particles found in the nucleus

neutrons

Neutral subatomic particles found in the nucleus

electrons

Negatively charged subatomic particles found outside the nucleus

atom

Basic unit of matter, consisting of protons, neutrons, and electrons

ion

Charged particle formed when an atom gains or loses electrons

isotope

Atoms of the same element with different numbers of neutrons

alpha radiation

Type of radiation consisting of alpha particles, which are helium nuclei

beta radiation

Type of radiation consisting of beta particles, which are high-energy electrons

gamma radiation

Type of radiation consisting of high-energy electromagnetic waves

half life

Time it takes for half of a radioactive substance to decay

nuclear fission

Process of splitting an atomic nucleus into two smaller nuclei

nuclear fusion

Process of combining two atomic nuclei to form a larger nucleus

atomic number

Number of protons in an atom

mass number

Total number of protons and neutrons in an atom

average atomic mass

Weighted average of the masses of all the isotopes of an element

mole

Unit of measurement for the amount of a substance

molar mass

Mass of one mole of a substance

dimensional analysis

Method of converting between different units using conversion factors