Periodic Table
Atomic Structure
Chemical Reactions
Types of Reactions
Scientists
100

All matter is composed of these.

What are atoms?

100

This is the center of an atom that makes up its mass. 

What is a nucleus?

100

In the reaction 2H₂ + O₂ → 2H₂O, the hydrogen and oxygen are these.

What are reactants?

100

Decomposition is the type of reaction where a substance does this.

What is break apart or break down?

100

This element is named after Niels Bohr.

What is Bohrium?

200

These columns on the periodic table can tell you the number of valence electrons per element.

What are groups?

200

This is the atomic number of oxygen.

What is 8?

200

When reactants break down and recombine as products, it is called this.

What is a chemical reaction?

200

2Na + Cl₂ → 2NaCl is an example of this type of reaction.

What is synthesis?

200

This is the theory that Isaac Newton developed.

What is the theory of gravity?

300

This group of elements is on the far right side of the periodic table and is known for being very stable (non-reactive).

What are the noble gases? 

300

One of the three subatomic particles that has no significant mass and has a negative charge.

What is an electron?

300

A molecule that speeds up chemical reactions.

What is a catalyst?

300

The excess energy from this type of reaction is often released through heat.

What is exothermic?

300
Isaac Newton was known for establishing these laws.

What are the laws of motion?

400

The highly reactive elements in group one of the periodic table, excluding hydrogen, are referred to as these.

What are alkali metals?

400

Each period or row on the periodic table includes elements that have this in common.

What is the number of electron shells?

400

This law states that matter is never created nor destroyed.

The Law of Conservation of Mass

400

Photosynthesis is an example of this type of reaction.

What is endothermic?

400

Jane Goodall spent two years in Africa studying these.

What are apes/chimpanzees?

500

These are the three main types of elements on the periodic table.

What are metals, metalloids, and nonmetals?

500

This is the name for the electrons in the outermost shell of an atom that are involved in chemical reactions.

What are valence electrons?

500

In a closed system, the mass of reactants will be __________ the mass of products.

What is equal to/the same as?

500

This type of reaction is always exothermic.

What is Combustion?

500

This scientist is best known for formulating the Periodic Law and creating a better version of the periodic table of elements.

Who is Dmitri Mendeleev?