First Semester Review

Neutrons have    charge.

• positive
• negative
• variable
• none (neutral)

Electrons have    charge.

• positive
• negative
• variable
• no

Protons have    charge.

• positive
• negative
• variable
• no

A certain atom has 26 protons, 26 electrons, and 30 neutrons. Its mass number is ____.

• 26
• 30
• 52
• 56

Where are electrons of an atom found?

• Nucleus
• Electron Cloud
• Some are in the nucleus and some in the electron cloud.
• They are moving everywhere.

An atom has an atomic number of 15 and a mass number of 31. How many protons are there in the atom?

• 15
• 31
• 16
• 47

Which of these is the proton.

• A
• B
• C
• None

Which of these is the electron?

• A
• B
• C
• D

B and C are found in the ______ of an atom.

• Energy levels
• Space
• Nucleus
• Outside

How many protons does this atom have?

• 2.5
• 6
• 5
• 10.811