Download Name Subatomic Particles Date: Chemistry!

Name ________________
Subatomic Particles
Date:_________________
1. The mass of a proton is approximately equal to the mass of
1) an alpha particle 2) an electron
3) a neutron
4) a positron
2. What is the mass number of a carbon atom that contains six protons, eight neutrons, and six electrons?
1) 6
2) 8
3) 14
4) 20
3. Which two particles make up most of the mass of a hydrogen-2 atom?
1) electron and neutron
2) electron and proton
3) proton and neutron
4) proton and positron
4. The mass of a calcium atom is due primarily to the mass of its
1) protons, only
2) neutrons, only
3) protons and neutrons
4) protons and electrons
5. The mass of a proton is approximately equal to the total mass of 1,836
1) electrons
2) neutrons
3) helium nuclei
4) alpha particles
6. What is the mass number of an atom that consists of 20 protons, 20 neutrons, and 18 electrons?
1) 18
2) 20
3) 38
4) 40
7. The atomic mass of an atom is measured in atomic mass units. This unit is based on
1) 1H
2)
14N
3)
16O
4)
12C
the mass of a 3)
atom
16O
the mass of a 4)
atom
19F
8. An atomic mass unit is defined as exactly
1)
the mass of a 2)
atom
12C
14N
the mass of a
atom
9. An atom that contains 8 protons, 8 electrons, and 9 neutrons has
1) an atomic number of 9
2) an atomic number of 16
3) a mass number of 17
4) a mass number of 25
10. What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?
1) 19
2) 20
3) 39
4) 58
11. What is the total number of neutrons in the nucleus of a neutral atom that has 19 electrons and a mass
number of 39?
1) 19
2) 20
3) 39
4) 58
Chemistry!
Answer Key
Protons, Neutrons and Electrons
1.
3
2.
3
3.
3
4.
3
5.
1
6.
4
7.
4
8.
1
9.
3
10.
3
11.
2
Chemistry!