Lesson 6

Question 1

is the study of reactions involving changes in atomic nuclei.

Answer 1

Nuclear Chemistry

Question 2

Nuclear chemistry all started with the discovery of natural radioactivity by __________

Answer 2

Antoine Becquerel

Question 3

All nuclei contain two kinds of fundamental particles, ____________

Answer 3

proton and neutron

Question 4

Some nuclei are unstable; they emit particles and/or electromagnetic
radiation spontaneously and this is known as ________________

Answer 4

radioactivity.

Question 5

All elements having an atomic number greater than __________ are radioactive.

Answer 5

83

Question 6

The symbol 0 -1 e represents an electron in or from an ___________

Answer 6

atomic orbital.

Question 7

The symbol 0 -1 betarepresents an electron that, although physically identical to any other
electron, comes from a _____________-

Answer 7

nucleus

Question 8

The ________ has the same mass as the electron, but bears a +1 charge.

Answer 8

positron

Question 9

The ____ particle has two protons and two neutrons, so its atomic number is 2 and its mass
number is 4.

Answer 9

α

Question 10

The total number of protons plus neutrons in the products and in the reactants must be the
same (conservation of _____________).

The total number of nuclear charges in the products and in the reactants must be the same
(conservation of ___________).

Answer 10

-mass number
-atomic number

Question 11

we know that like charges repel and unlike charges attract one
another. Protons to repel one another strongly.

Answer 11

coulumb’s law

Question 12

If repulsion outweighs attraction, the nucleus ___________, emitting
particles and/or radiation.

If attractive forces prevail, the nucleus is ______.

Answer 12

-disintegrates
-stable

Question 13

The principal factor that determines whether a nucleus is stable.

Answer 13

Neutron-to Proton Ratio (n/p) -

Question 14

Stable atoms of elements having low atomic number has n/p value is close to ___

Answer 14

1

Question 15

Nuclei that contain 2, 8, 20, 50, 82, or 126 protons or neutrons are generally more stable than nuclei
that do not possess these numbers. The numbers 2, 8, 20, 50, 82, and 126 are called ________

Answer 15

magic numbers

Question 16

beta decay

Answer 16

decrease #of neutrons by 1
increase # of protons by 1

Question 17

positron

Answer 17

increase # of neutrons by 1
decrease number of protons by 1

Question 18

electron capture decay

Answer 18

increase # of neutrons by 1
decrease number of protons by 1

Question 19

alpha decay

Answer 19

decrease # of neutrons by 2
decrease number of protons by 2

Question 20

is the result from the bombardment of nuclei by neutrons,
protons, or other nuclei.

Answer 20

nuclear transmutation

Question 21

• elements with atomic numbers greater than 92.

Answer 21

Transuranium elements

Question 22

__________ made it possible to synthesize the so-called transuranium elements.

Answer 22

Particle accelerators

Question 23

is the process in which a heavy nucleus (mass number. 200) divides to
form smaller nuclei of intermediate mass and one or more neutrons.

Answer 23

nuclear fission

Question 24

The first nuclear fission reaction to be studied was that of ___________ bombarded with
slow neutrons, whose speed is comparable to that of air molecules at room temperature.

Answer 24

uranium-235

Question 25

a self- sustaining sequence of nuclear fission reactions.

Answer 25

nucear chain reaction

Question 26

the combining of small nuclei into larger ones, is largely exempt from
the waste disposal problem.

Answer 26

nuclear fusion

Question 27

Nuclear fusion occurs constantly in the _______ because it is made up mostly of hydrogen and
helium.

Answer 27

sun

Question 28

Because fusion reactions take place only at very high temperatures, they are often
called _________________.

Answer 28

thermonuclear reactions

Question 29

thermonuclear reactions/nuclear fusion take place at extremely high temperatures, on the order of _____________ to overcome the repulsive forces between the nuclei.

Answer 29

100 million
degrees Celsius,