13.3-13.4 Science

Question 1

true or false: the nuclei of most atoms are stable, but the nuclei of some isotopes are unstable, capable of breaking up or otherwise changing into another type of atom

Answer 1

true

Question 2

particles or electromagnetic waves given off when an atomic nucleus breaks up or undergoes a change

Answer 2

nuclear radiation

Question 3

any substance that is unstable

Answer 3

radioactive

Question 4

the breakup or change of an atomic nucleus from a higher-energy state to a lower-energy state, emitting radiation

Answer 4

radioactive decay

Question 5

the length of time required for half of an original substance to decay into a new substance

Answer 5

half-life

Question 6

radioactive decay that occurs when an unstable atom ejects a clump of two protons and two neutrons

Answer 6

alpha decay

Question 7

radioactive decay that occurs when a neutron in an atom’s nucleus changes into a proton, emitting an electron

Answer 7

beta decay

Question 8

radioactive decay that occurs when an excited nucleus releases energy without a change in the number of protons or neutrons

Answer 8

gamma decay

Question 9

nuclear radiation that can harm living things by disrupting the chemical processes within cells

Answer 9

ionizing radiation

Question 10

the process whereby a heavy nucleus is split into several pieces by bombarding it with neutrons

Answer 10

nuclear fission

Question 11

the situation in which free neutrons released by nuclear fission cause other atoms to undergo nuclear fission and release more neutrons

Answer 11

chain reaction

Question 12

the minimum amount of fissionable material that must be present for a chain reaction to occur

Answer 12

critical mass

Question 13

a device that works by initiating an uncontrolled nuclear fission chain reaction

Answer 13

atomic bomb

Question 14

a device that harnesses controlled fission to produce useful energy

Answer 14

nuclear reactor

Question 15

a nuclear reactor that recycles spent nuclear fuel to produce more than it uses

Answer 15

breeder reactor

Question 16

the process of combining two nuclei to form a heavier nucleus and thereby releasing energy

Answer 16

nuclear fusion

Question 17

another name for nuclear fusion reactions

Answer 17

thermonuclear reactions

Question 18

a weapon that uses nuclear fusion to release a tremendous amount of energy

Answer 18

hydrogen bomb

Question 19

any of the electrons in the outer shell of an atom

Answer 19

valence electron

Question 20

the rule stating that an atom tends to react in a way that fills its valence shell with eight electrons

Answer 20

Octet rule

Question 21

the law that states that elements show regular and repeating properties when they are arranged by their increasing atomic numbers

Answer 21

periodic law

Question 22

a table of the elements arranged by atomic number and number of valence electrons

Answer 22

periodic table of the elements

Question 23

1. a row of the periodic table
2. a column of the periodic table

Answer 23

1. period
2. group

Question 24

any of the elements in groups 1, 2, and 13-18 of the periodic table

Answer 24

main-group element

Question 25

any of the group of elements that are typically hard, dense, shiny solids; are good conductors of heat and electricity, and have high melting points

Answer 25

metal

Question 26

any of the group of elements that are typically poor conductors of electricity and heat

Answer 26

nonmetal

Question 27

all solids that have properties intermediate between metals and nonmetals

Answer 27

semimetal

Question 28

any element in group 1

Answer 28

alkali metal

Question 29

_______ is not included in the alkali metals because it has very different properties

Answer 29

hydrogen

Question 30

1. most abundant element in the human body 2. second most abundant element in the human body 3. third most abundant element in the human body

Answer 30

1. oxygen 2. carbon 3. hydrogen

Question 31

any element in group 2

Answer 31

alkaline earth metal

Question 32

any element in groups 3-12

Answer 32

transition metal

Question 33

any of the metals that lie beneath the main body of the periodic table, between groups 3 and 4; the Lanthanoids and Actinoids

Answer 33

inner transition metals

Question 34

Group 16 is called _____

Answer 34

chalcogens

Question 35

meaning “salt former” is any element in group 17

Answer 35

halogen

Question 36

any element in group 18

Answer 36

noble gas

Question 37

formerly called the “inert” gasses because it was believed that they did not react with any other element

Answer 37

noble gasses