Chapter 2: The Chemical Basis Of Life

Question 1

Matter

Answer 1

Anything that takes up space and has mass

Question 2

Element

Answer 2

A substance that can not be broken down into other substances by ordinary chemical means

Question 3

What elements are all living organisms mostly composed of?

Answer 3

Oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus

Question 4

Atomic Theory

Answer 4

The atomic theory states that elements consist of atoms

Question 5

Atomic symbol

Answer 5

The name given to an element and it’s atoms. This name is represented by one or two letters.

Question 6

What are the three types of subatomic particles?

Answer 6

Neutrons, electrons, and protons

Question 7

Neutrons

Answer 7

A subatomic particle that has no electrical charge

Question 8

Protons

Answer 8

A Subatomic particle that has a positive charge

Question 9

Electrons

Answer 9

A subatomic particle that has a negative charge

Question 10

Where are the protons and neutrons located within a cell?

Answer 10

The nucleus

Question 11

Where are the electrons located in an atom?

Answer 11

Electrons move around the nucleus

Question 12

The mass number of an atom is equal to what?

Answer 12

The sum of its protons and neutrons

Question 13

What is the difference between mass and weight?

Answer 13

Mass is constant but weight is associated with gravity

Question 14

Atomic mass

Answer 14

The average of the mass numbers for the atoms of elements

Question 15

Noble gases

Answer 15

The atoms in group 8 of the periodic table

Question 16

Isotopes

Answer 16

Atoms of the same element that differ in the number of neutrons

Question 17

Isotopes have the same number of protons but the they have different what?

Answer 17

Mass numbers

Question 18

Octet rule

Answer 18

The octet rule states that if an atom has 2 or more shells, the outer shell is most stable when it has 8 electrons

Question 19

Valence shell

Answer 19

An atom’s outermost shell

Question 20

Molecule

Answer 20

A group of atoms bonded together

Question 21

Compound

Answer 21

A molecule that contains atoms of more than one element

Question 22

What are the two primary types of chemical bonds?

Answer 22

Ionic and covalent

Question 23

Ionic bond

Answer 23

Attraction between opposite charges

Question 24

Covalent bond

Answer 24

When 2 atoms share electrons in order to have a completed outer shell

Question 25

How does an ionic bond form?

Answer 25

It forms when 2 atoms are held together by the attraction between opposite charges

Question 26

Ions

Answer 26

Charged atoms

Question 27

Salts

Answer 27

Solid substances that usually separate and exist as individual ions in water

Question 28

What are three types of bonds

Answer 28

Hydrogen, ionic, and covalent

Question 29

Which bond is the strongest

Answer 29

Covalent

Question 30

Which bond is the weakest?

Answer 30

Hydrogen

Question 31

Double covalent bonds

Answer 31

2 atoms share 4 electrons

Question 32

Reactants

Answer 32

Molecules that participate in the reaction

Question 33

Products

Answer 33

Molecules formed by the reaction

Question 34

What is the most important molecule on earth

Answer 34

Water

Question 35

Electronegativity

Answer 35

An Atom’s affinity for electrons in a covalent bond.

Question 36

Polar

Answer 36

A covalent bond in which electrons are not equally shared

Question 37

Hydrogen bond

Answer 37

Positive hydrogen atoms in one molecule attracted to the to the negative oxygen atoms in other water molecules

Question 38

Hydrophilic

Answer 38

Molecules that are attracted to water

Question 39

Hydrophobic

Answer 39

Nonionized and nonpolar molecules that are not attracted to water

Question 40

What are some properties of water that are important to life

Answer 40

Solvent, cohesion, adhesion, high surface tension, high heat capacity, high heat of vaporization, varying density and ice is less dense than water

Question 41

Solvent

Answer 41

Able to dissolve other substances

Question 42

Cohesion

Answer 42

The ability of water molecules to cling to each other do to hydrogen bonding

Question 43

Adhesion

Answer 43

The ability of water molecules to cling to other polar surfaces

Question 44

What is the difference between an acid and a base?

Answer 44

An acid has more hydrogen ions and a base has More hydroxide ions

Question 45

Acids

Answer 45

substances that dissertate in water releasing hydrogen ions

Question 46

Bases

Answer 46

Substances that either take up hydrogen ions or release hydroxide ions

Question 47

pH

Answer 47

A mathematical way of indicating the number of hydrogen ions in a solution

Question 48

pH scale

Answer 48

A scale that is used to indicate the Acidity or Basicity of a solution

Question 49

What does a pH of seven represent

Answer 49

A neutral state in which the hydrogen ions and hydroxide ion concentrations are equal

Question 50

What is the range of the pH scale

Answer 50

0 to 14

Question 51

Buffer

Answer 51

A chemical or a combination of chemicals that keeps pH within established limits

Question 52

What is the most abundant element by weight in the human body

Answer 52

Oxygen

Question 53

Why does water freeze from the top down

Answer 53

Because ice is less dense than water