The smallest unit of a substance that retains all of its properties (smallest unit of matter)

• atom

• compound

• molecule

• cell

Answer explanation

The smallest unit of matter that retains all properties is an atom.

Tags

NGSS.MS-PS1-1

These make up the nucleus of the atom

• proton

• neutron

• electron

• megatron

Answer explanation

The nucleus of an atom is made up of protons and neutrons. Electrons are found outside the nucleus. Megatron is not a part of an atom's nucleus. Neutrons and protons are the correct choices.

Tags

NGSS.HS-PS1-8

These are found in the "cloud" and are responsible for the interactions between atoms.

• protons

• neutrons

• electrons

• magnatrons

Answer explanation

Electrons are responsible for the interactions between atoms in the cloud.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The charge of a proton.

• positive (+)

• negative (-)

• neutral (0)

Answer explanation

The charge of a proton is positive (+).

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

The charge of a neutron.

• positive (+)

• negative (-)

• neutral (0)

Answer explanation

The charge of a neutron is neutral (0).

The charge of an electron.

• positive (+)

• negative (-)

• neutral (0)

Answer explanation

The charge of an electron is negative (-).

Tags

NGSS.HS-PS2-4

When an atom has more or less neutrons than normal, it is known as a/an

• ion

• isotope

• compound

• molecule

Answer explanation

An atom with more or less neutrons than normal is called an isotope. Isotopes have different numbers of neutrons but the same number of protons and electrons.

An isotope of an element is still the same element, but it differs in the

• atomic number

• average atomic mass

• mass number

• atomic symbol

Answer explanation

An isotope of an element is the same element but differs in the mass number. Isotopes have the same atomic number and atomic symbol, but different mass numbers.

Tags

NGSS.HS-PS1-8

Identify two differences between Carbon-12 and Carbon-14

• Different amounts of neutrons

• Different mass

• Different amounts of protons

• Different atomic symbols

Answer explanation

Carbon-12 and Carbon-14 differ in neutron count and mass. These differences distinguish the correct choices.

Tags

NGSS.HS-PS1-8

When an atom loses or gains electrons, it becomes a/an

• ion

• isotope

• new element

Answer explanation

When an atom loses or gains electrons, it becomes an ion. An ion is formed when an atom gains or loses electrons, resulting in a positive or negative charge.