Chapter 2

Question 1

Define matter

Answer 1

Any object in the universe that has mass and occupies space

Question 2

Name the 3 subatomic particles of an atom

Answer 2

protons, neurons and electrons

Question 3

Atomic number

Answer 3

The number of protons in a cell. the number of protons is equal to the number of electrons

Question 4

Define element

Answer 4

Any substance that cannot be broken down into any other substance by chemical means

Question 5

Atomic Mass

Answer 5

the sum of the masses of an atoms protons and electrons

Question 6

Cation

Answer 6

A positive ion, one that has more protons than electrons

Question 7

Anion

Answer 7

a negative ion that , one that has more electrons than protons

Question 8

Isotopes

Answer 8

Atoms of an element that differ in the number of neurons.

Question 9

define orbital

Answer 9

Areas around a nucleus where electrons are likely to be found

Question 10

Name the four and their shapes

Answer 10

S orbital - Sphere shaped\
P orbital - infinity shaped
d orbital - dumbbell shaped
f orbital - clover leaf shaped

Question 11

Explain why isotopes of an element behave the same

Answer 11

Electrons determine the chemical behaviour of an atom, since isotopes have the same amount of electrons, they will behave in the same manner.

Question 12

Energy levels

Answer 12

Discrete levels that correspond with the quanta( specific amount of energy)
The further an electron is from the nucleus, the higher t its potential energy

Question 13

Mass

Answer 13

Amount of a substance

Question 14

weight

Answer 14

The force that gravity exerts on an object

Question 15

organic compounds are made of

Answer 15

carbon, oxygen, hydrogen and nitrogen

Question 16

Nobel Gases

Answer 16

elements that have eight electrons in their outermost energy level, which makes them non - reactive and stable

Question 17

molecule

Answer 17

a group of atoms held together by energy in a stable association

Question 18

ionic bonds

Answer 18

bonds that result when ions with opposite charges attract one another

Question 19

covalent bonds

Answer 19

bonds that result when atoms share one or ore pairs of electrons , the strength increases with the number of shared electrons

Question 20

Polar covalent bonds

Answer 20

Formed by unequal sharing of electrons

Results in some partially negative and some partially positive parts of a molecule

Question 21

Nonpolar covalent Bond

Answer 21

Formed by equal sharing of electrons

Question 22

hydrogen bonds

Answer 22

weak bonds that water molecules form between each other and other polar compounds

Question 23

cohesion

Answer 23

The ability of water molecules to be attracted to one another

Question 24

Adhesion

Answer 24

Attraction for other polar molecules

Question 25

Specific heat

Answer 25

the amount of energy that 1g of a substance must absorb in order to change its temperature by 1 degree Celsius

Question 26

Heat of vaporisation

Answer 26

the amount of energy required to change 1g of a substance from a liquid to a gas

Question 27

hydration shell

Answer 27

when water molecules gather around any substance that carries an electrical charge

Question 28

hydrophobic

Answer 28

nonpolar molecules that do not readily form hydrogen bonds with water

Question 29

hydrophilic

Answer 29

polar molecules which readily form bonds with water molecules

Question 30

hydrophobic exclusion

Answer 30

the tendency of nonpolar molecules to aggregate in water

Question 31

mole

Answer 31

the weight of a substance in grams that corresponds with the atomic masses of all of the atoms in a molecule of that substance

Question 32

PH Scale

Answer 32

( power of hydrogen) A more convenient way of expressing the hydrogen ion concentration of a solution. it expresses the concentration as the negative logarithm of the molar concentration of the hydrogen ion

Question 33

Acid

Answer 33

any substance that dissociates in water to increase the hydrogen ion concentration .(Proton donors)

Question 34

Base

Answer 34

Any substance that combines with hydrogen ions when dissolved in water to decrease the molar concentration of hydrogen ions

Question 35

buffer

Answer 35

any substance that resists change in Ph

Question 36

rules regarding orbitals and energy levels

Answer 36

no orbital can contain more than two electrons, but an energy level can have more than one orbital

Question 37

How many elements are found in significant amounts in living organisms?

Answer 37

12

Question 38

How does the structure of water lead to the formation of hydrogen bonds

Answer 38

the polar covalent bonds in water molecules lead to the formation of hydrogen bonds

Question 39

Which properties of water lead to capillarity

Answer 39

cohesion and adhesion

Question 40

Describe how hydrogen bonding affects the properties of water

Answer 40

solid water is less dense than liquid water because the hydrogen bonds space the molecules further apart

Question 41

explain the relevance of waters unusual properties for living organisms

Answer 41

Waters high specific heat prevents a rapid change in temperature Waters high heat of vaporisation allows cooling through evaporation

Question 42

which two ions form when water dissociates

Answer 42

hydrogen and hydroxide ions

Question 43

which Ph rage indicates acids

Answer 43

1 to 6, with 1 being the most acidic

Question 44

which Ph rage indicates Bases

Answer 44

8 to 14, 8being the most basic