An Earthy hint
Periodicals
Metallics
Boom, Bang
Da Bomb
100

This old English word referred to an oxidized compound.

Earth.

100

Though not pretty nor perfect, how many categories are there on the Periodic Table?

10

100

This word dennotes the shine. 

Lustre

100

This neutral solvent causes the Alkali Metals to react.

Water.

100

This element is usually found in nuclear weapons.

Uranium

200

This color and fruit is also the oxidized compound of Calcium.

Lime.

200

The periodic table boasts this number of elements.

118

200
Iron, Colbalt, and Nickel share this trait in common.

Magnetism

200

Francium's episodic half-life 

22 Minutes
200

This synthesizer of the Planetary model also helped to develop intial theories in nuclear physics

Neils Bohr

300

This white powdery compound is also found in the Magnesium-rich Periclase.

Magnesia
300

This measurement of Atomic weight is 1/12 of a carbon atom.

Atomic Mass Unit.

300

This metal is canonically privileged for chalices and patens 

Gold

300

This element's reaction to water is used to make fireworks

Cesium

300

This part of New York was also the codename for initial attempts to make the atomic bomb.

Manhattan

400

This Strontium Oxide is used to protect X-ray patients from radiation. 

Strontia

400

Plutonium, Neputnium, Promethium are all examples of this type of unnatural element.

Synthetic.

400

This Transition metal was often used in the production of sewer pipes.

Lead
400

This reactive metal is used as a mental-health medicine.

Lithium
400

These mean cajoles were the callsigns for the American bombs dropped on Japan.

Little Boy and Fat Man

500

This gem is derived from Beryllium

Emerald

500

Radon, Xenon, and Argon are all these.

Noble Gases

500

These three metals unique for low density are found in the Alkali Metals. 

Lithium, Potassium, Sodium

500

This process purifies Uranium from dross and alien elements. 

Enrichment

500

In 2017, negotiations between the U.S and Iran stipulated that Iran's nuclear enrichment should be no higher than this number.

60%