PhET Build an Atom Activity Guide Flashcard A

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element.

Front

What are the three main subatomic particles?

Back

Protons, neutrons, and electrons.

Front

What is the charge of a neutron?

Back

Neutral (no charge).

Front

What is the charge of an electron?

Back

Negative.

Front

How do you calculate the mass number of an atom?

Back

The mass number is the sum of protons and neutrons in the nucleus.

Front

What is the atomic number?

Back

The atomic number is the number of protons in the nucleus of an atom.

Front

What is the relationship between protons and electrons in a neutral atom?

Back

In a neutral atom, the number of protons equals the number of electrons.

Front

What element has 7 protons?

Back

Nitrogen.

Front

What is the mass number of an atom with 26 protons and 30 neutrons?

Back

The mass number is 56 (26 protons + 30 neutrons).

Front

What is the charge of a proton?

Back

Positive.