structure of matter

Question 1

branch of science dealing with the chemistry of life forms

Answer 1

biochemistry

Question 2

anything that has weight and takes up space

Answer 2

matter

Question 3

chemical substance with only one type of atom

Answer 3

element

Question 4

substance composed of two or more chemically bonded elements

Answer 4

compound

Question 5

basic chemical substance needed in large quantity

Answer 5

bulk element

Question 6

basic chemical substance needed in small quantity

Answer 6

trace element

Question 7

basic chemical substance needed in very small quantity

Answer 7

ultratrace element

Question 8

the smallest complete unit of the elements

Answer 8

atom

Question 9

central core of an atom

Answer 9

nucleus

Question 10

a small negatively charged particle that encircles the nucleus of an atom

Answer 10

electron

Question 11

positively charged particle in an atomic nucleus

Answer 11

proton

Question 12

electrically neutral subatomic particle

Answer 12

neutron

Question 13

the number of protons in the atom of a particular element

Answer 13

atomic number

Question 14

the number of protons plus the number of neutrons in each of an element’s atoms

Answer 14

atomic weight

Question 15

an atom that have the same atomic number but different atomic weight

Answer 15

isotope

Question 16

the state in which an isotope is unstable

Answer 16

radioactive

Question 17

the energy or atomic fragments the unstable isotopes emit

Answer 17

atomic radiation

Question 18

particle composed of two or more joined atoms

Answer 18

molecule

Question 19

abbreviation for the number of atoms of each element in a compound

Answer 19

molecular formula

Question 20

substance composed of two or more chemically bonded elements

Answer 20

compound

Question 21

connection between atoms in a compound

Answer 21

bond

Question 22

the path formed by an electron or several electrons encircling the nucleus of an atom at a particular energy level

Answer 22

electron shell

Question 23

another name for electron shell because electrons have a level of energy characteristic of the particular shell they are in

Answer 23

energy shell

Question 24

rule that says atoms react in a way that leaves the outermost shell completely filled with electrons to achieve a more stable structure

Answer 24

octet rule

Question 25

to not be able to form chemical bonds because the outermost electron shell is filled; inactive

Answer 25

inert

Question 26

an atom that becomes electrically charged from gaining or losing electrons

Answer 26

ion

Question 27

a positively charged ion

Answer 27

cation

Question 28

a negatively charged ion

Answer 28

anion

Question 29

a bond where ions with opposite charges attract each other

Answer 29

ionic bond

Question 30

bond produced when two atoms share electrons

Answer 30

covalent bond

Question 31

representation of the way atoms bond to form a molecule, using symbols for each element and lines to indicate chemical bonds

Answer 31

structural formula

Question 32

electrical charge not distributed symmetrically

Answer 32

polar

Question 33

the attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule

Answer 33

hydrogen bond

Question 34

the starting material that are changed by the chemical reaction

Answer 34

reactant

Question 35

the atom, ions, or molecule formed at the reaction's conclusion

Answer 35

product

Question 36

process by which substances are united to form a new type of substance

Answer 36

synthesis

Question 37

the breakdown of molecules into simpler compounds

Answer 37

decomposition

Question 38

chemical reaction in which parts of two kinds of molecules trade positions

Answer 38

exchange reaction

Question 39

chemical reaction in which the end products can change back into the reactants

Answer 39

reversible reaction

Question 40

a molecule that influences the rates (not the direction) of chemical reactions but are not consumed in the process

Answer 40

catalyst

Question 41

substance that dissolves in water and releases ions

Answer 41

electrolyte

Question 42

substance that ionizes in water to release hydrogen ions

Answer 42

acid

Question 43

substance that ionizes in water, releasing hydroxide ions (OH-) or other ions that combine with hydrogen ions

Answer 43

base

Question 44

compound produced by a reaction between an acid and a base

Answer 44

salt

Question 45

shorthand notation for the hydrogen ion concentration used to indicate the acidic or alkaline condition of a solution

Answer 45

pH scale

Question 46

releasing equal numbers of acidic hydrogen ions and basic hydroxide ions

Answer 46

neutral

Question 47

increase in the alkalinity of body fluids above pH 7.45

Answer 47

alkalosis

Question 48

increase in acidity of body fluids below pH 7.35

Answer 48

acidosis

Question 49

a chemical that resist pH change

Answer 49

buffer