Chapter 2

Question 1

matter

Answer 1

anything that takes up space and has mass

Question 2

mass

Answer 2

a measure of the amount of matter an object contains

Question 3

weight

Answer 3

a measure of how strongly an object is pulled by earth’s gravity. Can vary with the distance from the earth’s center

Question 4

element

Answer 4

a substance that cannot be broken down into other substances by chemistry

Question 5

molecule

Answer 5

a substance consisting of atoms held together by covalent bonds

Question 6

compound

Answer 6

a substance composed of 2 or more elements combined in a fixed ratio

Question 7

What are the “big 6” elements and their symbols?

Answer 7

1. C – Carbon
2. H – Hydrogen
3. N – Nitrogen
4. O – Oxygen
5. P – Phosphate
6. S – Sulfur

Question 8

Name 6 other elements as discussed in lecture

Answer 8

1. Cl – Chlorine
2. Fe – Iron
3. Na – Sodium
4. K – Potassium
5. Ca – Calcium
6. Zn – Zinc

Question 9

atom

Answer 9

the smallest unit of matter that still keeps the physical and chemical properties of its element

Question 10

What are the subatomic particles of an atom, their charges, and their location?

Answer 10

Neutron - no charge - nucleus - 1 dal
Proton - +1 - nucleus - 1 dal
Electron - -1 - electron shell, orbital level - 1/2000 of 1 dal

Question 11

atomic number

Answer 11

the number of protons in an atom of a particular element

• the number is unique for each element.
• if neutral atom, protons and electrons are equal

Question 12

mass number

Answer 12

the number of protons and neutrons in an atom

- can be used to determine the number of neutrons by subtracting the atomic number from this number

Question 13

molecular weight/ mass

Answer 13

the sum of atomic masses/weights of all the atoms in a molecule
- expressed in units of daltons or A.M.U. (atomic mass units)

Question 14

isotopes

Answer 14

atoms of an element that have the same atomic number, but different mass numbers

• different mass because different number of neutrons
• some can be radioactive

Question 15

Which subatomic particle is directly involved in chemical reactions?

Answer 15

electrons (e-) because they are in the electron shell

Question 16

What are the rules for energy shells and electrons?

Answer 16

1. max of 2 electrons in the innermost electron shell
2. electrons must occupy innermost shell first before filling the next
3. 2nd can hold 8 electrons (rest can too)
4. atoms will attempt to have a full shell of electrons (octet rule)

Question 17

Name the types of chemical bonds

Answer 17

1. Covalent bond
2. Ionic bond
3. Weak bonds (hydrogen bonds)

Question 18

Covalent bonds

Answer 18

occurs when electrons are shared

• very strong
• can be single, double, or tripled based on pairs of electrons shared.

Question 19

What are the types of covalent bonds?

Answer 19

Nonpolar- equal electron sharing

Polar - unequal electron sharing.

Question 20

Ionic bonds

Answer 20

• formed by complete transfer of an electron from 1 atom to another
• forms salts (NaCl)

Question 21

ion

Answer 21

a charged atom or molecule

Question 22

anion

Answer 22

a negatively charged ion (gains an electron)

Question 23

cation

Answer 23

a positively charged ion (loses an electron)

Question 24

hydrogen bonds

Answer 24

Hydrogen atom covalently bonded to one atom but is attracted to another

Question 25

heat

Answer 25

the total kinetic energy due to molecular motion in a body of matter

Question 26

temperature

Answer 26

- measure of heat intensity to the average kinetic energy of molecules in a body of H2O - heat passes from warmer objects to cooler objects

Question 27

calorie (cal)

Answer 27

the amount of heat needed to raise the temperature of 1 g of water by 1 C

Question 28

Why does H2O have a fairly high specific heat?

Answer 28

It takes a great deal of energy to break apart the hydrogen bonds that connect different water molecules

Question 29

Vaporization / evaporation

Answer 29

the transformation of a substance from a liquid to a gaseous state

Question 30

Heat of vaporization

Answer 30

the quantity of heat a liquid must absorb for 1 gram to be converted to the gaseous state - H2O has a high _____ ___ _________ ~540g

Question 31

Why is water important to the body?

Answer 31

1. it is a very good solvent 2. water can gain or lose a great deal of heat without major changes in its own temperature 3. used to help build up or break down many different compounds 4. exhibits cohesion: the linking of 2 molecules to another of the same type usually with Hydrogen bonds

Question 32

Due to the hydrogen bonding, water is _____ dense as a solid than as a liquid.

Answer 32

less

Question 33

evaporative cooling

Answer 33

the cooling of a liquid's surface when the liquid changes to a gaseous state

Question 34

solution

Answer 34

a liquid that is a homogenous mixture of 2 or more substances

Question 35

solvent

Answer 35

the dissolving agent of a solution (dissolver)

Question 36

solute

Answer 36

the substance dissolved in the solution

Question 37

hydrophilic

Answer 37

"water loving" has a strong affinity (attraction) for water

Question 38

hydrophobic

Answer 38

"water fearing" | term used to describe a condition where water is repelled

Question 39

molecular weight/mass

Answer 39

the sum of the atomic masses/weights of all the atoms in the molecule Expressed in units of daltons and A.M.U. (atomic mass unit)

Question 40

mole

Answer 40

the amount of a substance that has a mass in grams equivalent to its molecular mass/weight in daltons

Question 41

Avogadro's number

Answer 41

A mole of 1 substance has the same number of molecules as a mole of another =6.022x10623

Question 42

Molarity (M)

Answer 42

the number of moles of solute per L of solution

Question 43

acid

Answer 43

a substance which breaks apart in solution to release or donate hydrogen ions

Question 44

base

Answer 44

a substance which removes hydrogen ions from a solution

Question 45

pH

Answer 45

the concentration of H+ ions in a solution = -log[H+]

Question 46

pH ____ when the acidity level _____

Answer 46

- decreases, increases | - increases, decreases

Question 47

buffer

Answer 47

a substance that can stabilize pH by either removing or releasing H+ into the solution as needed.

Question 48

salts

Answer 48

inorganic compounds that dissolve in water, but do not release H+ or OH- - Held together by ionic bonds

Question 49

hydroxyl group

Answer 49

R--OH- Alcohols

Question 50

carboxyl group

Answer 50

O ll R--C--OH Carboxylic acids

Question 51

Amino group

Answer 51

H l R--N--H Amines

Question 52

sulfhydryl group

Answer 52

R--SH Thiols

Question 53

phosphate groups

Answer 53

``` O ll R--O--P--O- l O- organic phosphate ```

Question 54

Methyl group

Answer 54

``` H l R--C--H l H ``` methyl (methylated)

Question 55

carbonyl group

Answer 55

O ll R--C--R Ketone or Aledhyde

Question 56

Carbohydrates

Answer 56

- composed of C, H, and O atoms in a fixed ratio of 1:2:1 | - Basic building blocks are simple sugars known as monosaccharides