Physical Science Fall Semester Exam 2024

Front

What is a valence electron?

Back

Electrons in the outermost energy level of an atom.

Front

If an atom has 9 protons and 10 electrons, what is its charge?

Back

-1

Front

How many neutrons does C-14 contain?

Back

8

Front

What must an atom with 12 positively charged subatomic particles have to be neutral?

Back

12 electrons

Front

What makes up most of the mass in an atom?

Back

Protons and neutrons.

Front

What is the atomic number of an element?

Back

The number of protons in the nucleus of an atom.

Front

What is a chemical reaction?

Back

A process that involves the rearrangement of the molecular or ionic structure of a substance.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed.

Front

What are reactants in a chemical reaction?

Back

Substances that undergo change during a chemical reaction.