Periodic Table Groups
Atomic Theory Timeline
Atomic Structure
Isotopes
Periodic Table
100

Is Sodium a Metal or Nonmetal?

Metal

100

The first greek philosopher to say that atoms are indivisible particles. 

Democritus

100

The charge of a neutron.

neutral

100

The meaning of the number at the end of the isotope name. (behind the hyphen)

mass

100

The last name of the man that is considered father of the periodic table.

Mendeleev

200

The third main group that has properties of both Metals and Nonmetals.

Metalloids

200

The name of the model that states that electrons move on orbits around the nucleus.

Bohr model

200

The two subatomic particles located in the nucleus.

proton and neutron

200

Number of neutrons in the isotope Oxygen-19

11

200

The number of total groups on the periodic table. 

18

300

The group name of elements in column 18.

Noble Gases

300

The name of the most current theory.

Quantum mechanical model

300

The number of neutrons in Neon. 

10

300

Atomic number of the Isotope Uranium-238

92

300

Number of natural elements. 

94

400

The group name of the column that includes Fluorine.

Halogens

400

First and Last Name of the scientist who developed the plum-pudding theory. 

JJ Thomson

400

Number of valence electrons of Lithium. 

1

400

Number of Protons in the Isotope Sulfur-37

16

400

The direction in which atomic size increases.

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