atomic structure

Question 1

atom

Answer 1

smallest particle of an element that retains its identity in a chemical reaction

Question 2

electrons

Answer 2

negatively charged particles

Question 3

protons

Answer 3

positively charged particles

Question 4

neutrons

Answer 4

particles with no charge

Question 5

nucleus

Answer 5

central core of an atom composed of protons and neutrons

Question 6

atomic number

Answer 6

number of protons in the nucleus. Number of protons also equals number of electrons

Question 7

mass number

Answer 7

total number of protons and neutrons in an atom

Question 8

isotopes

Answer 8

atoms that have the same number of protons but different number of neutrons

Question 9

Atomic mass unit

Answer 9

1/12th of the mass of a carbon 12 atom

Question 10

atomic mass

Answer 10

a weighted average mass of the atoms in a naturally occurring sample of the element

Question 11

radioactivity

Answer 11

the spontaneous emission of rays or particles emitted from a certain element

Question 12

nuclear radiation

Answer 12

rays and particles emitted from a radioactive source

Question 13

radioisotope

Answer 13

unstable isotope

Question 14

Alpha particle

Answer 14

2 4 H e , where He is the chemical symbol for helium, the subscript 2 is the number of protons, and the superscript 4 is the mass number (2 protons + 2 neutrons)

Question 15

beta particle (electron)

Answer 15

e or beta symbol with a subscript of -1 and a superscript of 0

Question 16

gamma ray

Answer 16

γ with a subscript and superscript of 0

Question 17

positron

Answer 17

e or beta symbol with subscript of+1 and superscript of 0

Question 18

neutron

Answer 18

n with subscript of 0 and superscript of 1

Question 19

proton

Answer 19

p or H with sub and superscript of 1

Question 20

nuclear force

Answer 20

attractive force that acts between all nuclear particles that are close together

Question 21

band of stability

Answer 21

region containing stable nuclei in a neutron vs. proton

Question 22

half llife

Answer 22

time required for one-half of the nuclei in a radioisotope to decay

Question 23

transmutation

Answer 23

conversion of an atom of one element into an atom of another element

Question 24

fission

Answer 24

when the nuclei of certain isotopes are bombarded with neutrons, the nuclei split into smaller fragments

Question 25

neutron moderation

Answer 25

process that slows down neutrons so the reactor fuel can capture them to continue the chain reaction

Question 26

neutron absorption

Answer 26

decreases the number of slow moving neutrons

Question 27

fusion

Answer 27

occurs when the nuclei combine to produce a nucleus of greater mass

Question 28

Half life equation

Answer 28

A=(initial amount)(.5)^(elapsed time/half life)