Section 17.3- Nuclear Reactions

Question 1

nuclear equations must follow two important rules

Answer 1

1. the mass number must be conserved
2. the nuclear charge (atomic number) must be conserved

Question 2

in nuclear equations, the _____________- are not used in the finding of the mass number and nuclear charge

Answer 2

electrons

Question 3

two main types of radioactive decay

Answer 3

alpha decay
beta decay

Question 4

a high-speed electron

Answer 4

beta decay

Question 5

alpha decay and beta decay may involve the emission of high energy electromagnetic waves called

Answer 5

gamma rays

Question 6

some other types of nuclear reactions may involve the EMISSION OF HIGH SPEED NEUTRONS as

Answer 6

neutron radiation

Question 7

occurs when an unstable atom ejects a clump of two protons and two neutrons called an alpha particle in order to reach a more stable state

Answer 7

alpha decay

Question 8

alpha decay is the most common type of decay in elements with

Answer 8

Z > 83

Question 9

alpha particles are actually

Answer 9

2+ ions of helium-4

Question 10

occurs when a neutron in an atom’s nucleus changes into a proton and emits and electron in the process

Answer 10

beta decay

Question 11

the electron emitted from the nucleus

Answer 11

beta particle

Question 12

the beta particle is identical to all other electrons except for its

Answer 12

origin

Question 13

uses for beta decay

Answer 13

self-luminous watches
firearm sights
exit signs

Question 14

electromagnetic waves of very high frequency and energy

Answer 14

gamma radiation

Question 15

releases gamma radiation (electromagnetic waves of very high frequency and energy)

Answer 15

gamma decay

Question 16

gamma decay often occurs in nuclei that have just undergone ______________ or are in an excited state

Answer 16

alpha or beta decay

Question 17

uses for gamma decay

Answer 17

cancer treatment

Question 18

types of nuclear reactions that cause neutron to be ejected from the nucleus, forming

Answer 18

neutron radiation

Question 19

the chief use of neutron radiation is the

Answer 19

production of transuranium elements by bombardment reactions

Question 20

the four types of radiation discussed vary greatly in their ability to

Answer 20

penetrate matter

Question 21

lowest to highest order of decay penetration

Answer 21

1. alpha
2. beta
3. gamma
4. neutron

Question 22

the decay rate of a substance can be stated as its

the length of time it takes for 1/2 of the original substance to decay into the new substance

Answer 22

half-life

Question 23

the amount of nuclide remaining after each half-life is

Answer 23

one half of what you started with

Question 24

to find the amount of nuclide remaining after a given time

Answer 24

1. find the number of hlaf-lives contained in the given time period
2. raise (.5) to the power of this number, and
3. multiply the original mass of nuclide by the value obtained in step 2

Question 25

an important principle to remember is that the half-life of a substance determines the

Answer 25

intensity of the radiation it produces

Question 26

the amount of decay occurring in a radioactive substance is known as the

Answer 26

activity

Question 27

is measured by counting the number of nuclear disintegrations that occur per second

Answer 27

the activity of radioactive nuclide

Question 28

the SI unit of activity defined as one nuclear disintegration per second

Answer 28

becquerel (bq)

Question 29

the shorter the half-life, the ______________ the radioactivity

Answer 29

greater

Question 30

because a Bq is a small unit, an older unit called __________ is still used

Answer 30

curie (Ci)

Question 31

1curie (Ci) =

Answer 31

3.7 x 10 ^ 10 Bq

Question 32

the new atom that results when an unstable atom undergoes nuclear decay

Answer 32

daughter element or daughter nuclide

Question 33

the result of the process of seeking to find a stable nuclide through the production of daughter nuclides is a long series of radioactive nulcides ending in a nonradioactive (stable) nuclide; such a chain of nuclides is a

Answer 33

radioactive decay series

Question 34

nuclear reactions induced by pelting a sample with other particles are called

Answer 34

bombardment reactions

Question 35

uses magnetic and electric fields to accelerate charged particles to energies of several million electron volts to initiate nuclear reactions

Answer 35

particle accelerators

Question 36

all the elements beyond uranium that have been artificially prepared by bombardment reactions, although some of them occur naturally by trace amounts

Answer 36

transuranium elements