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Flashcards in Chapter 9 Deck (31):
1

Radioactivity

process by which some atoms emit energy and particles

2

Isotope

Same number of protons but different mass numbers
(different number of neutrons)

3

Nuclide

any atom characterized by an atomic number and a mass number

4

Alpha Particle

slow moving, 2 protons 2 neutrons (He),

5

Beta Particle

B symbol, fast-moving (90% speed of light). Involves a neutron converting to a proton. No mass

6

Gamma Rays

Y symbol, most energetic part, not considered matter

7

Positron

Proton converts to neutron, Beta Particle

8

Ionizing radiation

collective name for alpha, beta, gamma radiation. leaves a trail of ions throughout the material it penetrates

9

Nuclear Equation

can be used to represent the process of radioactive decay a nuclide breaks down, producing a new nuclide, smaller particles , and/or energy

10

m represents?

metastable isotope, meaning that it is unstable and increases its stability through gamma decay without change to mass or charge of the isotope

11

Binding energy

measure of nuclear stability of the nucleus

12

Half-life

is the time required for one-half of a given quantity of a substance to undergo change

13

Radiocarbon dating

estimation of the age of objects through measurement of isotopic ratios of carbon

14

Nuclear reactor

heat energy converted to liquid water into steam, which produces electricity

15

Fission

occurs when a heavy nuclear particle is split into smaller nuclei by a smaller nuclear particle

16

Chain reaction

when neutrons create a chain reaction

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Fusion

(meaning to join together) results from the combination fo two small nuclei to form a larger nucleus with the concurrent release of large amounts of energy

18

Breeder reactor

variation of a fission reactor that literally manufactures its own fuel

19

Nuclear medicine

use of radiation in the treatment of various forms of cancer, as well as diagnosing diseases/cancers/etc..

20

Nuclear imaging

medical techniques involving tracers

21

Tracers

small amounts of radioactive substances used as probes to study internal organs

22

Natural radioactivity

naturally occurring

23

ficial radioactivity

non-radioactive nucleus is made radioactive

24

Background Radiation

level of radiation attributable to our surroundings on a day-to-day basis

25

Shielding

a way to protect from harmful radiation

26

Curie

measure of the amount of radioactivity in a radioactive source

27

roentgen

measure of very high energy ionizing radiation (x-ray & gamma) only

28

Rad

radiation absorbed dosage, provides more meaningful information than either of the previous units of measure

29

Rem

describes the biological damage caused by the absorption of different kinds of radiation of the human body

30

Lethal dose (LD50)

is defined as the acute dosage of radiation that would be fatal for 50% of the exposed population within 30 days.

31

Stability of an isotope

- Ratio of neutrons to protons
– Nuclei with large number of protons (84 or more) tend to be unstable
– The “magic numbers” of 2, 8, 20, 50, 82, or 126 help
determine stability these numbers of protons or neutrons are stable
– Even numbers of protons or neutrons are generally
more stable than those with odd numbers
– All isotopes (except 1 H) with more protons than neutrons are unstable