Nature of Atoms (Chapter 2)

Question 1

matter has _____ and occupies _____

Answer 1

mass/space

Question 2

all matter is composed of _____

Answer 2

atoms

Question 3

atomic number

Answer 3

number of protons in an atom (protons equal electrons)

Question 4

element

Answer 4

any substance that can not be broken down to any other substance by ordinary chemical means

Question 5

mass

Answer 5

refers to amount of substance

Question 6

weight

Answer 6

refers to force of gravity exerted on substance

Question 7

atomic mass

Answer 7

sum of protons and neutrons

Question 8

each proton and neutron has a mass of approximately 1 ______

Answer 8

dalton

Question 9

isotope

Answer 9

atoms of a single element that possess different numbers of neutrons

Question 10

half-life

Answer 10

time it takes for one half of the atoms i. s sample to decay

Question 11

electron

Answer 11

negatively charged particles located in orbitals

Question 12

neutral atoms have ____ number of electrons and protons

Answer 12

same

Question 13

cation

Answer 13

more protons than electrons (positively charged)

Question 14

anion

Answer 14

fewer protons than electrons (negative charge)

Question 15

borh model

Answer 15

electrons in discrete orbits

Question 16

energy levels

Answer 16

electrons father from the nucleus have more energy

Question 17

valence electrons

Answer 17

number of electrons in outermost energy level

Question 18

octet rule

Answer 18

atoms tend to establish completely full outer energy levels

Question 19

there are __ naturally occurring elements

Answer 19

92

Question 20

only __ elements are found in living organisms in substantial amounts

Answer 20

12

Question 21

_____, _______, _______ and ______ make up 96.3% of human body weight.

Answer 21

carbon, hydrogen, oxygen, and nitrogen (CHON)

Question 22

molecules

Answer 22

groups of atoms held together in a stable association

Question 23

compounds

Answer 23

molecules containing more than one type of element

Question 24

chemical bonds

Answer 24

how atoms are held together in molecules/compounds

Question 25

ionic bonds

Answer 25

former my the attraction of oppositely charged ions

Question 26

____ or ____ of electrons forms ions

Answer 26

gain/loss

Question 27

metals ____ electrons and no metals ____ electrons to achieve an octet

Answer 27

lose/gain

Question 28

covalent bond

Answer 28

form when atoms share two or more valence electrons

Question 29

cohesion

Answer 29

polarity of water allows water molecules to be attracted to one another

Question 30

properties of water

Answer 30

1. water has a high specific heat 2. water has a high heat of vaporization 3. solid water is less dense than liquid water 4. water has a good solvent (it’s polar) 5. water organizes nonpolar molecules 6. water can form ions

Question 31

acid

Answer 31

any substance that dissociates in water to increase the H+ content and lower the pH

Question 32

base

Answer 32

substance that lowers the H+ concentrate and increases the pH

Question 33

buffer

Answer 33

substance that resists changes in pH by either releasing H+ when a base is added or absorbing H+ when acid is added

Question 34

Body buffering of blood pH levels

Answer 34

H+ + HCO3- H2CO3 H2O+CO2

Question 35

R-O-H

Answer 35

hydroxyl

Question 36

R-CH3

Answer 36

methyl

Question 37

O | | R-C-R

Answer 37

carbonyl

Question 38

``` O | | C / \ R OH ```

Answer 38

carboxyl

Question 39

``` H / R-N \ H ```

Answer 39

Amino

Question 40

``` O | | R P-OH \ / \ O OH ```

Answer 40

phosphate

Question 41

R-S-H

Answer 41

sulfhydryl