1st Semester Exam prep

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the atomic mass of an element?

Back

The atomic mass is the weighted average mass of an element's isotopes, measured in atomic mass units (amu).

Front

What is the difference between atomic number and atomic mass?

Back

The difference is the number of neutrons in the atom.

Front

What is an endothermic reaction?

Back

An endothermic reaction is a chemical reaction that absorbs heat energy from its surroundings.

Front

How does an endothermic reaction feel to the touch?

Back

It feels cold to the touch because it absorbs heat energy.

Front

What happens to the total mass in a chemical reaction?

Back

According to the law of conservation of mass, the total mass remains the same before and after the reaction.

Front

What occurs when water changes from steam to liquid?

Back

The water molecules move slower and occupy less space.

Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically bond together.

Front

Give an example of a compound.

Back

Ammonia (NH3) is an example of a compound.

Front

What is the role of protons in an atom?

Back

Protons determine the atomic number and identity of an element.