Section 17.1- Nuclear Chemistry/Radioactivity: Changes in the Nucleus

Question 1

the study of reactions involving the nucleus is

Answer 1

nuclear chemistry

Question 2

the atom’s dense central core in which change may occur

Answer 2

nucleus

Question 3

changes in the electron shells of an atom lead to __________________, while changes in the nucleus of an atom lead to __________________

Answer 3

chemical reaction
nuclear reactions

Question 4

scientists who found that thorium and its compounds radiate invisible rays just like uranium; they named this phenomenon radioactivity

Answer 4

Pierre and Marie Curie

Question 5

two radioactive elements that the Curies discovered

Answer 5

polonium
radium

Question 6

the nucleus of an atom contains two types of particles

Answer 6

positive-charged protons
uncharged neutrons

Question 7

determines the identity of the element

Answer 7

the number of protons in the nucleus (atomic number)

Question 8

the total number of protons and neutron in the nucleus

Answer 8

mass number

Question 9

atoms of the same element that differ in their mass numbers are

Answer 9

isotopes

Question 10

most atoms and isotopes that we have studied so far are ___________: they show no tendency to break up or suddenly change into other elements

Answer 10

stable

Question 11

the nuclei of isotopes in which the protons and neutrons are held together rather loosely are described as _________________ because they have a tendency to spontaneously shed subatomic particles or otherwise break apart

Answer 11

unstable

Question 12

both the particles and electromagnetic waves produced by a nuclear reaction are called

Answer 12

nuclear radiation

Question 13

the phenomenon of an unstable element continually emitting energy as its atoms decay

Answer 13

radioactivity

Question 14

unstable substances that are named because of their tendency to undergo nuclear decay and thereby emit nuclear radiation

Answer 14

radioactive

Question 15

a specific type of atom described by both its atomic number and mass number

any isotope of any element

Answer 15

nuclide

Question 16

radioactive nuclides is often shortened to

Answer 16

radionuclides

Question 17

two forms of radiation

Answer 17

radioactive particles
energy

Question 18

different types of radiation

Answer 18

1. alpha
2. beta
3. gamma

Question 19

radiation occurs when a substance is ___________ and gives of rays to become more _____________

Answer 19

unstable to stable

Question 20

consist of subatomic particles moving at high speed

Answer 20

alpha rays and beta rays

Question 21

a clump of 2 protons and 2 neutrons

Answer 21

alpha particle

Question 22

a high-speed electron

Answer 22

beta particle

Question 23

high-energy electromagnetic waves, similar to uv rays or electromagnetic waves but more powerful

Answer 23

gamma rays