Study Guide: Chapter 2

Question 1

Most common elements in living things

Answer 1

oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus

Question 2

Atom

Answer 2

smallest unit of matter that still retains the properties of an element. named from greek word meaning “indivisible”

Question 3

Proton

Answer 3

subatomic particle with single positive electrical charge

Question 4

Electron

Answer 4

subatomic particle with single negative electrical charge

Question 5

Neutron

Answer 5

electrically neutral has no charge

Question 6

Atomic Number

Answer 6

the number of protons in each atom of a particular element

Question 7

Isotope

Answer 7

one of several atomic forms of an element each have the same number of protons but different number of neutrons

Question 8

Chemical Bond

Answer 8

an attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. the bonded atoms gain complete outer electron shells

Question 9

Ionic Bond

Answer 9

a chemical bond resulting from the attraction between oppositely charged ions

Question 10

Hydrogen Bond

Answer 10

a type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative hydrogen atom of a polar covalent bond in another molecule

Question 11

Reactants (Chemical Reaction)

Answer 11

a starting material in a chemical reaction

Question 12

Products (Chemical Reaction)

Answer 12

an ending material in a chemical reaction

Question 13

pH scale

Answer 13

a measure of the acidity of a solution, ranging in value 0 (most acidic) to 14 (most basic). pH stands for potential hydrogen and refer to the concentration of hydrogen ions (H+)

Question 14

special physical properties of water and why water has it

Answer 14

viscous
self-adhere
water is polar
Water is cohesive because of hydrogen bonds. cohesion creates surface tension and helps water to move from plant roots to leaves
Stronger resistance to temperature change because of hydrogen bonding
thermally stable- lots of energy to heat it up and cool it down
Higher boiling point-hydrogen bonds must break before molecules can move faster thus water absorbs a large amount of heat
Higher freezing point-water molecules slow down and more hydrogen bonds form releasing considerable amounts of heat
water is the solvent of life- polar or charged solutes dissolve when water surrounds them = aq. soln.
ice floats b/c less dense than liquid water

Question 15

element

Answer 15

a substance that cannot be broken down to other substances by chemical means

Question 16

compound

Answer 16

a substance containing two or more elements in a fixed ratio (ex. Water H20; 2 parts hydrogen for every one part oxygen)

Question 17

acid

Answer 17

a substance that donates hydrogen ions (H+) to solutions (ex. of acid HCl)

Question 18

base

Answer 18

a substance that reduces hydrogen ion (H+) concentration of a solution. Some bases do this by donating OH-. (ex. of base NaOH)