Chapter 2

Question 1

Atom

Answer 1

smallest unit of matter, nucleus contains protons/neutrons, orbitals in the electron cloud contain electrons

Question 2

Molecule

Answer 2

2+ atoms joined by a chemical bond

Question 3

Element

Answer 3

different types of atoms, 90 naturally occuring

Question 4

Atomic Number

Answer 4

the number of protons an atom has

Question 5

Atomic Weight

Answer 5

average weight of all isotopes found on earth (found on periodic table)

Question 6

Isotope

Answer 6

atoms of the same element that have different # of neutrons, most elements have a few isotopes

Question 7

Valence Shell

Answer 7

the outermost electron shell of an atom

Question 8

Octet Rule

Answer 8

atoms reacting to obtain full valence shell

Question 9

Electronegativity

Answer 9

How much an atom will attract shared electrons across a bond. O is more electronegative compared to N, C, H. N is more electronegative compared to C, H. C and H are similar in electronegativity.

Question 10

Ion

Answer 10

A charged atom

Question 11

Anion

Answer 11

a negative ion

Question 12

Cation

Answer 12

a positive ion

Question 13

Explain what is created if you change the number of protons

Answer 13

a different element

Question 14

Explain what is created if you change the number of neutrons

Answer 14

becomes an isotope

Question 15

Explain what is created if you change the number of electrons

Answer 15

becomes an ion

Question 16

ionic bonds

Answer 16

electrical attraction between 2 atoms

Question 17

covalent bonds

Answer 17

sharing electrons between 2 atoms

Question 18

hydrogen bond

Answer 18

weak electrical attraction between MOLECULES

Question 19

non-polar covalent bond

Answer 19

electrons are shared equally, usually same element (H2), or with similar electronegativity (C and H)

Question 20

polar covalent bond

Answer 20

electrons are not equally shared (O is more electronegative than H, electrons spend more time around O than H)

Question 21

solute

Answer 21

something that dissolves in a solvent

Question 22

solvent

Answer 22

liquid in which one or more substance can dissolve

Question 23

solution

Answer 23

solute and solvent

Question 24

Acid

Answer 24

LOW pH, high H+ concentration, something that can donate H+

Question 25

Base

Answer 25

HIGH pH, lowers H+ concentration, usually OH- ions, something that reacts with H+, removing H+ from the solution

Question 26

Buffer

Answer 26

Readily absorbs excess H+ or OH-, keeping body pH neutral

Question 27

Density of Ice

Answer 27

4 hydrogen bonds, in a lattice, more spread out than liquid, less dense= floats

Question 28

High Specific Heat

Answer 28

the amount of energy required to raise the temp of 1 gram of water 1 degree C

Question 29

High Heat of Vaporization

Answer 29

the amount of energy required to change 1 gram of water to gas. takes a lot of energy.

Question 30

Cohesion

Answer 30

attraction between 2 like things (water beads)

Question 31

Surface Tension

Answer 31

the capacity of a substance to withstand being ruptured when placed under tension or stress

Question 32

Adhesion

Answer 32

attraction between 2 different things (water attracted to glass, spreads out)

Question 33

Capillary action

Answer 33

adhesion allows for water to be attracted to the charged glass walls of the capillary tube

Question 34

Relate the structure/ bonds of water to the properties above in one sentence.

Answer 34

Hydrogen bonds between polar water molecules account for all the above properties of water.