Atoms & Periodic Table

What is the smallest unit of matter? It is composed of protons and neutrons, held together in the nucleus, and electrons around the nucleus in different electron orbitals, which form an electron cloud.

• cell

• nucleus

• atom

• electron

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

What is a subatomic particle with a positive charge that is in the nucleus of an atom?

• neutron

• proton

• electron

• valence electron

What is a subatomic particle without an electric charge, located in the nucleus of an atom?

• neutron

• proton

• electron

• valence electron

What is a subatomic particle with a negative charge? It is found in the electron cloud surrounding the nucleus.

• neutron

• proton

• electron

• electron cloud

What is the system of electrons surrounding the nucleus of an atom?

• valence electrons

• nucleus

• electrons

• electron cloud

What is the center of an atom containing protons and neutrons?

• nucleus

• neutron

• proton

• electron cloud

What is the number of protons in the nucleus of an atom that determines the chemical properties of an atom?

• mass number

• atomic mass

• atomic number

• atomic symbol

What is the combined mass of all the protons and neutrons of an atom and is approximately equal to the number of protons and neutrons?

• atomic mass

• atomic number

• subatomic particles

• nucleus weight

What happens to the number of shells as you move down a group?

• They decrease by 1

• They increase by 1

• Nothing

As you move left to right on a row or period what happens?

• Atomic number increases by 1

• Electrons decrease

• Number of shells decrease

• Nothing