Chemistry Unit Test

Question 1

What are the 3 types of Sub-atomic particles and how do you find their number on the periodic table?

Answer 1

Proton- Atomic Number
Neutron- Subtract # of protons from mass number
Electron- Same as protons

Question 2

How many groups of elements does the periodic table have?

Answer 2

18

Question 3

What are valence electrons and how can you use the periodic table to determine the number of them in an atom?

Answer 3

They are the electrons found in the outermost energy level of an atom, on the periodic table, use the group number but drop the teen

Question 4

What are the number of valence electrons for Hydrogen, Calcium, Oxygen,and Neon

Answer 4

Hydrogen-1
Calcium-2
Oxygen-6
Neon-8

Question 5

What are the noble gases and describe their bonding abilities

Answer 5

They are Neon, Argon, Krypton, Xenon, Radon, they do not form bonds with other atoms because they already have a full valence shell

Question 6

Why atoms considered neutral?

Answer 6

The number of electrons equal the number of protons

Question 7

Define and give an example of an ionic bond

Answer 7

bond that forms when electrons are transferred from one atom to another, which results in a positive and negative ion.-NaCl

Question 8

Define and give an example of a metallic bond

Answer 8

bond formed by the attraction between positively charged metal ions and the electrons around them- block of silver

Question 9

Define and give an example of a covalent bond

Answer 9

bond formed when atoms share one or more pairs of electrons- H2O

Question 10

Define Crystal Lattice

Answer 10

the regular patterns in which a crystal is arranged

Question 11

Define ion(s)

Answer 11

CHARGED particles when atoms gain or lose electrons

Question 12

Define atom(s)

Answer 12

NEUTRAL (no charge) because # of protons equal the # of neutrons

Question 13

Define diatomic molecule and give 3+ examples

Answer 13

atom make of 2 of the same molecules- Hydrogen, Oxygen, nitrogen, Fluorine, Chlorine, Bromine, Iodine

Question 14

Define chemical reaction

Answer 14

when one or more substances change to produce one or more different products

Question 15

what are the four signs of a chemical reaction?

Answer 15

Gas formation, solid formation, energy change, color change

Question 16

what happens during a chemical reaction?

Answer 16

bonds break, new bonds form, new substance created

Question 17

define product

Answer 17

substance that forms in a chemical reaction

Question 18

define reactant

Answer 18

substance that participates in a chemical reaction

Question 19

what does the law of conservation of mass state?

Answer 19

Mass cannot be created nor destroyed in a chemical reaction

Question 20

synthesis reaction

Answer 20

2 substances combine to form 1

Question 21

decomposition reaction

Answer 21

compound breaks down to form 2 or more substances

Question 22

single displacement reaction

Answer 22

1 element replaces another

Question 23

double displacement reaction

Answer 23

ions from 2 compounds exchange places

Question 24

define exothermic

Answer 24

energy (heat) RELEASED in a chemical reaction

Question 25

define endothermic

Answer 25

energy (requires heat) is taken in during a chemical reaction

Question 26

define activation energy

Answer 26

minimum amount of energy need to start a chemical reaction- striking a match, spark in a car’s engine, light

Question 27

define acid and give properties

Answer 27

liquid with pH level below 7- sour flavor, many corrosive, react with metals, conduct electric current

Question 28

define base and give properties

Answer 28

liquid with a pH level above 7- bitter flavor, many corrosive, slippery feel, conduct electric current

Question 29

define indicator and give examples

Answer 29

substance that changes color in the presence of an acid or base- bromythol blue, pH paper, pH meter, litmus paper strips

Question 30

what 2 substances are always produced in chemical reaction

Answer 30

a salt and water

Question 31

in chemistry, what is a salt?

Answer 31

an ionic compound that forms when a metal replaces the hydrogen of an acid

Question 32

define radioactivity

Answer 32

process by which an unstable nucleus gives off nuclear radiation

Question 33

name the 3 types of radioactive decay

Answer 33

alpha, beta, gamma

Question 34

which RD has the most penetrating power?

Answer 34

gamma

Question 35

name one use of radioactivity in home, industry, and healthcare

Answer 35

home- smoke detectors
industry-space probes
healthcare- tracers

Question 35

Define isotope

Answer 35

atom that has the same number of protons as other atoms of the same element but have a different number of neutrons

Question 36

define half-life

Answer 36

time needed of half a sample of a radioactive substance to undergo radioactive decay

Question 37

fission

Answer 37

splitting of the nucleus of one large atom into 2 or more fragments

Question 38

fusion

Answer 38

combo of nuclei of small atoms to form a larger nucleus

Question 39

what process occurs in nuclear power plants?

Answer 39

fission

Question 40

what process occurs in the sun’s core, what state of matter is found, and what temp does it have to be?

Answer 40

Fusion- state of matter- plasma- more than 100,000,000 degrees celsius

Question 41

fusion advantages

Answer 41

less accident prone, less waste, endless supply of fuel in the oceans

Question 42

fusion disadvantages

Answer 42

difficult to create, more energy used to create than is produced

Question 43

fission advantages

Answer 43

cost less that plants that use fossil fuels, no pollution

Question 44

fission disadvantages

Answer 44

more accidents, must be stored until it becomes less radioactive