Chapter 21 - Nuclear Chemistry

Question 0

Atomic number

Answer 0

Number of protons

Question 1

Nucleons

Answer 1

Protons, neutrons, electrons

Nucleus is composed of the first two

Question 2

Mass of atom

Answer 2

Number of protons and neutrons

Question 3

Isotopes happen because

Answer 3

Varying neutrons

Question 4

Radioactive

Answer 4

Unstable

Not uncommon for nuclides aka radionuclides

Question 5

Alpha decay

Answer 5

Loss of an alpha particle (a helium nucleus)

Question 6

Beta decay

Answer 6

Loss of the beta particle (a high energy electron)

Question 7

Positron emission

Answer 7

Nuclei decay by emitting a positron a particle hay has the same mass as but and opposites charge to that of an electron
0
e
1

Question 8

Gamma emission

Answer 8

The loss of a gamma ray which is high energy radiation that almost always accompanies the loss of a nuclear particle
0
0

Question 9

Electron capture

Answer 9

Addition of an electron to a proton in the nucleus

Result is a neutron

Question 10

Neutron-proton ratios

Answer 10

Any element with more than one proton will have repulsions between the protons in the nucleus

Question 11

What helps keep the nucleus from flying apart?

Answer 11

A strong nuclear force

Question 12

Neutrons key role

Answer 12

Stabilizing the nucleus

The ratio of neutrons to protons is an important factor

Question 13

For smaller nuclei the neutron - proton ratio

Answer 13

Is close to 1:1 when z< 21

Question 14

As nuclei get larger the number of neutrons needed to stabilize the nucleus

Answer 14

Increases

Question 15

Belt of stability

Answer 15

Blue dark dots that show what nuclides would be stable

Question 16

Above the belt of stability

Answer 16

Above the belt have too many neutrons (tend to be emitting beta particles)

Question 17

Below the belt of stability

Answer 17

Nuclei have too many protons

Can become more stable by positron emission or electron capture

Question 18

There are no stable nuclei with an atomic number greater than

Answer 18

83

These nuclei tend to decay by alpha emission

Question 19

Large radioactive nuclei and stabilization

Answer 19

Cannot stabilize from one nuclear transformation

Undergo a series of decays often forming a nuclide of lead

Question 20

Trends of number of protons and neutrons dealing with stability

Answer 20

Even is more stable than odds

Question 21

How can one tap all the energy of a nucleus

Answer 21

Nuclear fission

Starts with the bombardment with a neutron which causes the decay and production of more neutrons (nuclear chain reaction)

Question 22

Critical mass

Answer 22

Rate of neutron loss = rate of neutron creation by fission

Question 23

Manhattan project

Answer 23

Development of the a bomb in WWII

Lead by Oppenheimer and groves

Used uranium 235

Question 24

Curie/becquerel

Answer 24

Amt of radiation emitted by material

Question 25

Rad/gray

Answer 25

Radiation dose absorbed by a person

Question 26

Rem/sievert

Answer 26

Biological risk of exposure to radiation

Question 27

Geiger counter

Answer 27

Used to measure the amount of activity present in radioactive sample

Detects current of ions

Question 28

Kinetics of radioactive decay

Answer 28

Nuclear transmutation is a first order process

Kinetics of such a process obey this eqn: ln(Nt/N0) = -kt

Question 29

Half life of radioactive decay

Answer 29

0.693/k

Question 30

Radiocarbon dating

Answer 30

By comparing amount of a radioactive nuclide present at a given point in time with the amount normally present we can find the age of an object

Question 31

Nuclear reactors

Answer 31

In nuclear reactors the heat generated by the reaction is used to produce steak that turns a turbine connected to a generator

Reaction is kept in check by control rods by blocking the paths of some neutrons

Question 32

Nuclear accidents

Answer 32

Three mile island
Chernobyl
Fukushima

Question 33

How can nuclear transformations be induced

Answer 33

By acceleration a particle and colliding it with the nuclide

Question 34

Particle accelerator

Answer 34

Enormous
Circular tracks
Radii is miles long

Question 35

Nuclear fusion

Answer 35

Superior method of generating power

Products not reactive
To achieve fusion the material must be state of plasma (super hot)