Period/Groups
Important People
Symbols
Gases
Metals
100
Period containing Potassium
What is Period 4
100
Discovered the structure of the atom.
Who is Niels Bohr
100
B
What is Boron
100
He
What is Helium
100
Au
What is Gold
200
Period 4 Group 14
What is Germanium
200
Discovered the Electron.
Who is JJ Thomson
200
H
What is Hydrogen
200
N
What is Nitrogen
200
Ag
What is Silver
300
Period 4 Group 6
What is Chromium
300
Published the Periodic Table.
Who is Dmitri Mendleev
300
He
What is Helium
300
F
What is Fluorine
300
Pt
What is Platium
400
Period 6 group 9
What is Iridium
400
demonstrated the nuclear nature of atoms by deflecting alpha particles passing through a thin gold foil.
Who is Ernest Ruthford
400
K
What is Potassium
400
O
What is Oxygen
400
Ir
What is Iridium
500
Group 18, period 4
What is Krypton
500
Proposed the atomic Universe
Who is Democrotus
500
Tm
What is Thulium
500
Xe
What is Xenon
500
Tm
What is Thulium