5.1 Atoms and Elements

What is the heavy core of an atom called?

• Electron

• Proton

• Neutron

• Nucleus

What is the mass number of an atom?

• The number of protons in an atom

• The number of neutrons in an atom

• The number of protons plus neutrons in an atom

• The number of electrons in an atom

How is the atomic mass calculated?

• Protons + Electrons

• Neutrons + Electrons

• Protons + Neutrons

• Protons - Neutrons

Which of the following is true for a neutral atom?

• Electrons = Protons

• Electrons = Neutrons

• Protons = Neutrons

• Atomic mass = Electrons

What is the best way to define an isotope?

• Same number of protons, different number of electrons

• Same number of protons different number of neutrons

• Same number of neutrons, different number of electrons

• Same number of neutrons, different number of protons

What is the common feature of all isotopes of hydrogen?

• They have the same number of neutrons

• They have the same number of protons

• They have the same mass number

• They have different atomic numbers

What is the charge of a proton?

• Positive

• Negative

• Neutral

• Variable

What is the charge of a neutron?

• Positive

• Negative

• Neutral

• Variable

If an element has an atomic number of 15 and a mass number of 31, how many neutrons does it have?

• 15

• 16

• 31

• 46

What is the mass number of an element with 8 protons and 8 neutrons?

• 8

• 16

• 24

• 32