Mass Number

A sodium atom has 11 protons. It has a mass number of 23. How many neutrons does it have?

• 11

• 23

• 12

• 5

Tags

NGSS.MS-PS1-1

A berilium atom has 4 protons. It has a mass number of 9. How many neutrons does it have?

• 5

• 4

• 9

• 8

Tags

NGSS.MS-PS1-1

A mercury atom has 80 protons. It has a mass number of 201. How many neutrons does it have?

• 201

• 121

• 80

• 281

Tags

NGSS.MS-PS1-1

A calcium atom has 20 protons. It has a mass number of 40. How many neutrons does it have?

Tags

NGSS.MS-PS1-1

If an element has 17 protons and 20 neutrons, what is its mass number?

• 17

• 10

• 20

• 37

If an element has 10 protons and 12 neutrons, what is its mass number?

What is the mass number defined as?

• the number of protons

• the number of protons and neutrons

• the number of neutrons

• the number of protons and electrons

What is the mass number of this atom?

• 1

• 3

• 4

• 7

Tags

NGSS.MS-PS1-1

A carbon atom has 6 protons. It has a mass number of 12. How many neutrons does it have?

• 6

• 12

• 18

• 0

An oxygen atom has 8 protons. It has a mass number of 16. How many neutrons does it have?

• 8

• 16

• 24

• 0

Tags

NGSS.MS-PS1-1