8.1

Question 1

democritus

Answer 1

first to have the idea of “an atom” being the smallest particle of all matter

Question 2

Dalton atomic model

Answer 2

Atoms of an element are similar to each other AND atoms combine with each other to form new kinds of compounds

Question 3

JJ Thomson

Answer 3

discovered the electron (assumed protons existed) and thought electrons were scattered randomly around. called plum pudding model

Question 4

rutherford atomic model

Answer 4

Nucleus in the center with a positive charge, and most of the atom is empty space where the electrons are

Question 5

rutherfords gold foil experiment

Answer 5

alpha particles were directed at a thin sheet of gold foil; most passed through the foil, but a few were deflected; this led to the discovery of the atomic nucleus

Question 6

niels bohr

Answer 6

1913- discovered that electrons move around the nucleus in orbits called electron shells

Question 7

cloud model of the atom

Answer 7

electrons move rapidly within a cloud like a region around the nucleus, not in set orbits

Question 8

chadwick atomic model

Answer 8

atomic model that realized that atoms have extra mass in the nucleus, and that mass was due to neutrons

Question 9

chronological order of atomic theory

Answer 9

D (democritus)
D (dalton)
T (thompson)
R (rutherford)
B (bohr)
C (cloud)
C (chadwick)