ch7 lesson

A radioactive element goes through a process in which its unstable atomic nucleus

changes into another more stable nucleus by emitting radiation.

• true

• false

Beneath each element’s symbol on the periodic table, there is a number that provides

the average mass of the element’s isotopes, weighted according to the abundance of

each isotope for the element.

• true

• false

Uranium is an example of an element that is able to spontaneously emit radiation.

• true

• false

Carbon-14 is the most abundant isotope of the element; it has a sum of protons and

neutrons equal to 14.

• true

• false

the number of protons in an atom of an element

• atomic number

• average atomic mass

the sum of the number of protons and neutrons

in an atom

• atomic number

• mass number

refers to an element that spontaneously emits

radiation

• nuclear decay

• isotope

type of nuclear decay in which a particle made

of one high-energy electron is emitted and a

neutron changes to a proton

• alpha decay

• gamma decay

type of nuclear decay in which a particle made

of one high-energy electron is emitted and a

neutron changes to a proton

• gamma decay

• beta decay

type of nuclear decay that does not emit particles

• beta decay

• gamma decay