Chapter 2

Question 1

Matter

Answer 1

Anything that occupies space and has mass.

Question 2

Element

Answer 2

Is a substance that cannot be broken down to other substances by ordinary chemical means. (92 in nature)

Question 3

Compound

Answer 3

Is a substance consisting of two or more different elements combined in a fixed ratio.

Question 4

make up 96% of all living matter.

Answer 4

Oxygen, Carbon, Hydrogen, and Nitrogen

Question 5

Trace Elements

Answer 5

Are essential for humans, but only in minute quantities.

Question 6

Iodine deficiency

Answer 6

causes the thyroid gland to grow to abnormal size, a condition called goiter.

Question 7

commonly added minerals to food

Answer 7

Iron , Fluoride

Question 8

Atom

Answer 8

Is the smallest unit of matter that still retains the properties of an element

Question 9

Proton

Answer 9

Is a subatomic particle with a single positive electrical charge. (+)

Question 10

Electron

Answer 10

Is a subatomic particle with a single negative charge. (-)

Question 11

Neutron

Answer 11

Is electrically neutral. (no charge)

Question 12

Nucleus

Answer 12

atoms central core. (2 Protons, 2 Neutrons)

Question 13

Atomic Number

Answer 13

All the atoms of a particular element have the same unique number of protons.v

Question 14

Mass Number

Answer 14

Is the sum of the number of protons and neutrons in its nucleus.

Question 15

Atomic Mass

Answer 15

is approximately to its mass number the sum of its protons and neutrons in daltons.

Question 16

Mass number vs atomic mass

Answer 16

All atoms of an element have the same atomic number, but some atoms of that element may differ in mass number. (This is because of Isotopes)

Question 17

Isotopes

Answer 17

The different isotopes of an element have the same number of protons and behave identically in chemical reactions, but they have different numbers of neutrons.

Question 18

Radioactive Isotope

Answer 18

is one in which the nucleus decays spontaneously, giving off particles and energy

Question 19

use of isotopes

Answer 19

isotopes can be used to track certain body functions by finding where the isotopes are in the body.

Question 20

Electron Shells

Answer 20

the location of electrons from the nucleus, each with a characteristic distance.

Question 21

first orbital and second orbital

Answer 21

The first orbital can hold 2, the second can hold 8 (4 pairs).

Question 22

Valence Shell

Answer 22

is the number of electrons present in the outermost shell

Question 23

Chemical Bonds

Answer 23

when two atoms with incomplete outer shells react, each atom will share, donate, or receive electrons so both have complete outer shells.

Question 24

Covalent Bond

Answer 24

two atoms, each with an unpaired electron in its outer shell, actually share a pair of electrons.

Question 25

Molecule

Answer 25

Are atoms held together by covalent bonds.

Question 26

Valence or bonding capacity

Answer 26

is the number of additional electrons needed to fill its valence shell.

Question 27

Electronegativity

Answer 27

an atom’s attraction for shared electrons.

Question 28

Non-polar covalent bonds

Answer 28

electrons that are shared equally between the atoms.

Question 29

Polar covalent bond

Answer 29

the pulling of shared negatively charged electrons closer to the more electronegative atom makes that atom partially negative and the other atom partially positive. (electron not shared equally)

Question 30

Ion

Answer 30

an atom or molecule with an electrical charge resulting from a gain or loss of one or more electrons.

Question 31

Ionic bond

Answer 31

Two Ions with opposite charges attract each other.

Question 32

Ionic bonds form

Answer 32

when one atom transfers an electron to another.

Question 33

Salt

Answer 33

a synonym for an ionic compound (Sodium Chloride).

Question 34

The fullness of a valence shell

Answer 34

determines the pattern of covalent bonding or ionization.

Question 35

Most strong bonds

Answer 35

are covalent.

Question 36

Hydrogen bond

Answer 36

one of the most important types of weak bonds

Question 37

what are the charges in a hydrogen bond

Answer 37

Oxygen slightly negative, Hydrogen slightly positive.

Question 38

Polar molecule

Answer 38

it has an un-equal distribution of charges

Question 39

Chemical Reactions

Answer 39

breaking existing chemical bonds and forming new ones.

Question 40

Cohesion

Answer 40

Tendency of molecules of the same kind to stick together.

Question 41

Adhesion

Answer 41

the cling of one substance to another.

Question 42

Surface tension

Answer 42

a measure of how difficult it is to stretch or break the surface of a liquid.

Question 43

Thermal energy

Answer 43

is the energy associated with the random movement of atoms and molecules.

Question 44

Heat

Answer 44

thermal energy transferred from warm to cold.

Question 45

Temperature

Answer 45

measures the intensity of heat, that is the average speed of molecules in a body of matter.

Question 46

Evaporative cooling

Answer 46

when a substance evaporates the surface of the liquid that remains behind cools down.

Question 47

Solution

Answer 47

is a liquid consisting of a uniform mixture of two or more substances.

Question 48

Solvent

Answer 48

The dissolving agent

Question 49

Solute

Answer 49

a substance that is dissolved

Question 50

Aqueous solution

Answer 50

is one in which water is the solvent

Question 51

Why is water a universal solvent

Answer 51

Positive hydrogen ends of water molecules attract to negative ions. Negative Oxygen ends of water molecules attracted to positive sodium ion.

Question 52

Acid

Answer 52

Donates hydrogen ions (H+)

Question 53

Base

Answer 53

is a substance that reduces the hydrogen ion concentration of a solution. (OH-)

Question 54

Buffer

Answer 54

A substance that accepts H+ when they are in excess and donates H+ when their concentration drops is called a buffer.