Atoms & Periodic Table

An element has an atomic number of 20. This means it has:

• 20 atoms in it.

• 20 protons.

• an atomic mass of 20.

• 20 neutrons.

Protons and electrons:

• have the same mass

• are both found in the nucleus.

• have opposite charges.

• are added together to find the atomic mass.

What is the atomic number of the atom shown in the picture?

• 13

• 14

• 1

• 27

Tags

NGSS.MS-PS1-1

What is true about the Periodic Table?

• Elements in the same Family have the same number of protons.

• Elements in the same Family have similar chemical properties.

• Elements in the same Family are shown in the same row.

• Elements in the same Family have the same number of electrons.

An atom is neutral if:

• it has the same number of protons and neutrons.

• it has the same number of protons and electrons.

• it has an even number of valence electrons.

• it has the same number of electrons and neutrons.

Which is an electron?

• A
• B
• C

Tags

NGSS.MS-PS1-1

What is found in the nucleus of atoms?

• Protons and electrons.
• Protons, neutrons, and electrons.
• Protons and neutrons.
• Neutrons and electrons.

Tags

NGSS.MS-PS1-1

Each row in the periodic table is called a 

• group
• period
• cluster
• unit

Each column in the periodic table is called a 

• period
• group
• cluster
• unit

The blue elements (left side) are called 

• metals
• nonmetals
• metalloids
• noble gases