Ch 2: Chemistry of Life

Question 1

Matter

Answer 1

anything that occupies space and has mass (solids, liquids, gas)

Question 2

Atoms

Answer 2

all matter consists of these; the smallest units that retain all of the properties of their type of matter (bonded to form molecules usually)

Question 3

Element

Answer 3

basic substance that cannot be broken down

Question 4

Compounds

Answer 4

individual elements that are combined

Question 5

Reactants

Answer 5

transformed into products through chemical reactions (chemical reactions are written with reactants on the left and products on the right)

Question 6

Atomic number

Answer 6

corresponds to the number of protons in an element (found on top of sumbol)

Question 7

Atomic weight

Answer 7

corresponds to the number of protons AND neutrons in an element (found under the symbol)

Question 8

4 elements; living things

Answer 8

Carbon, hydrogen, oxygen and nitrogen

Question 9

subatomic particles

Answer 9

how atoms themselves are composed

Question 10

protons

Answer 10

positive cahrge, located in nucleus, number of protons determines chemical element and also determine identity of an element

Question 11

neutrons

Answer 11

no charge, located in nucleus, number of neutrons determines isotope

Question 12

electrons

Answer 12

negative charge, orbit nucleus at high speeds, little mass, number of electrons determines atom’s in ion state and chemical reactivity

Question 13

Isotopes

Answer 13

variations of an element that differ in their neutron number (less stable and may decay over time, emitting radiation)

Question 14

Ions

Answer 14

charge atoms

Question 15

in a chemical reaction…

Answer 15

atoms gain, release, or share electrons

Question 16

Ionic bonds

Answer 16

involved the transfer of one or more electrons from one atom to another

Question 17

Covalent bones

Answer 17

involve sharing of one or more electrons between atoms

Question 18

Receiving atom

Answer 18

negatively charged

Question 19

Donating atom

Answer 19

positively charge

Question 20

Receiving and donating atom

Answer 20

held together by attraction of their opposite charges

Question 21

Nonpolar covalent

Answer 21

equal sharing of electrons

Question 22

Polar covalent

Answer 22

unequal sharing of electrons

Question 23

Hydrogen bond

Answer 23

fairly weak by itself but one water molecule may participate in serval hydrogen bonds and become strong enough to form liquid water

Question 24

Water Properties

Answer 24

frozen water floats, water is an effective solvent, water has a strong resistance to charge in temperatures, and water molecules stick together

Question 25

Solvent

Answer 25

dissolving agent, to form a mixture or solution

Question 26

Cohesion

Answer 26

tendency of molecules to stick together , water molecules have strong cohesion due to hydrogen bonding

Question 27

pH

Answer 27

measure of the acidity of a solution (0-14. Acidic-Basic). Each number represents tenfold change

Question 28

aqueous solution

Answer 28

Some water molecules break apart into hydrogen ions and hydroxide ions. This concentration determines pH

Question 29

Buffers

Answer 29

the way cells regulate their pH, chemicals that minimize changes in pH by accepting hydrogens ions (in our blood when we exercise for example)

Question 30

Carbon atoms

Answer 30

can form long and branching chains (skeletons for a wide variety of chemical compounds)

Question 31

Organic compounds

Answer 31

molecules that contain carbon bonded to other elements

Question 32

functional groups

Answer 32

sets of atoms that are attached to the carbon skeleton, play important roles in reactions with other compounds

Question 33

4 Classes of Organic Molecules

Answer 33

Carobhydrates, lipids, proteins, and nucleic acids