Exam-Atom Structure

Question 1

What is the fundamental unit of matter?

Answer 1

atom

Atoms are the basic building blocks of all substances.

Question 2

What is the center of an atom called?

Answer 2

nucleus

The nucleus contains protons and neutrons.

Question 3

What particle orbits the nucleus of an atom?

Answer 3

electron

Electrons are negatively charged particles.

Question 4

What is the term for the region around the nucleus where electrons are found?

Answer 4

electron cloud

The electron cloud represents the areas where electrons are likely to be located.

Question 5

What is the charge of a proton?

Answer 5

positive charge

Protons are positively charged particles found in the nucleus.

Question 6

What is the charge of a neutron?

Answer 6

neutral/no charge

Neutrons are neutral particles also found in the nucleus.

Question 7

What is the charge of an electron?

Answer 7

negative charge

Electrons carry a negative charge.

Question 8

What is the mass of a proton or neutron approximately measured in?

Answer 8

1 amu

The atomic mass unit (amu) is a standard unit of mass used to express atomic and molecular weights.

Question 9

What is the mass of an electron compared to protons and neutrons?

Answer 9

almost no mass

Electrons have a negligible mass compared to protons and neutrons.

Question 10

Fill in the blank: An atom is _______ if it has an equal number of protons and electrons.

Answer 10

neutral

A neutral atom has no overall charge.

Question 11

True or False: Neutrons are negatively charged.

Answer 11

False

Neutrons have no charge (they are neutral).