Ch. 2

Question 0

Electrons charge

Answer 0

Negative

Question 1

What are the properties of an atom?

Answer 1

Electrons, protons, neutrons

Question 2

Protons charge

Answer 2

Positive

Question 3

Neutrons charge

Answer 3

Neutral

Question 4

Atomic number

Answer 4

The number of protons in the nucleus that defines the element

Question 5

The Atomic mass

Answer 5

The number of protons plus the number of neutrons

Question 6

Isotopes

Answer 6

Forms of an element that have the same number of protons but differ in the number of neutrons their atoms carry

Question 7

Isotopes are atoms of an element that differ in _____

Answer 7

Mass number

Question 8

Atoms of ______ spontaneously emit subatomic particles or energy

Answer 8

Radioisotopes

Question 9

Radioactive decay

Answer 9

The process by which atoms of a radioisotope emit energy and/ or subatomic particles when their nucleus spontaneously decays

Question 10

Radioisotope

Answer 10

Isotope with an unstable nucleus

Question 11

Researchers use radio scopes to make ____ that track biological processes inside living organisms

Answer 11

Tracers

Question 12

Why do electrons matter to atoms ?

Answer 12

• they share and donate then

- whether atoms interact with other atoms depends on how many electrons they have

Question 13

What are Shell models?

Answer 13

Help us visualize how electrons arranged around the atoms nucleus from the innermost shell outward

Question 14

What is an ion?

Answer 14

The charge an atom with a different number of electrons and protons

Question 15

Electronegativity

Answer 15

A measure of how strongly an atoms attracts electrons from other atoms

Question 16

A ______ is an attractive force that unites two atoms as a ______ when their electrons interact.

Answer 16

Chemical bond, molecule

Question 17

Compound

Answer 17

A molecule that consists of two or more elements, productions of elements do not vary

Question 18

Mixture

Answer 18

An intermingling of substances, the proportions of the substances can vary because chemical bonds do not form

Question 19

The three types of chemical bonds:

Answer 19

1. Ionic bonds
2. Covalent bonds
3. Hydrogen bonds

Question 20

Ionic bond

Answer 20

A strong association between oppositely charged ions that arises from mutual attraction of opposite charges

Question 21

A _____ bond is formed when two ions are held together by the attraction of opposite electrical charges.

Answer 21

Ionic

Question 22

Covalent bond

Answer 22

Chemical bond in which two atoms share a pair of electrons

Question 23

Polarity

Answer 23

Any separation of charge into distinct positive and negative regions

Question 24

Hydrogen bond

Answer 24

Attraction that forms between a covalently bonded hydrogen atom and another atom taking part in a separate covalent bond

Question 25

_____ can form hydrogen bonds, non-polar molecules cannot.

Answer 25

Polar molecules

Question 26

Form between opposite charges in polar water molecules

Answer 26

Hydrogen bonds

Question 27

Water is essential to life because of its unique properties:

Answer 27

- solvent for salts and other polar solutes - resists temperature changes - cohesion

Question 28

Water is a ______ that easily dissolves salts, sugars, and other polar substances

Answer 28

Solvent

Question 29

Solvent

Answer 29

Liquid that can dissolve other substances

Question 30

Solute

Answer 30

A dissolved substance

Question 31

A compound that dissolves easily in water and releases ions

Answer 31

Salt

Question 32

Hydrophilic

Answer 32

Substance that dissolves easily in water

Question 33

Hydrophobic

Answer 33

Substance that resists dissolving in water such as oil. Usually non-polar molecules

Question 34

What is cohesion?

Answer 34

- Tendency of molecule to stick together - pulls water upward in plants - causes surface tension

Question 35

Cohesion of water molecules resists _____

Answer 35

Evaporation

Question 36

_____ stability is important for homeostasis; most molecules of life function within a certain temperature range

Answer 36

Temperature

Question 37

Temperature

Answer 37

Measure of molecular motion

Question 38

What is pH?

Answer 38

Measure of concentration of hydrogen ions in a fluid

Question 39

Concentration

Answer 39

Number of molecules or ions of a solute per unit volume of a solution

Question 40

Acid

Answer 40

Substance that releases hydrogen ions in water, the higher the number of ions , the lower the pH

Question 41

Base

Answer 41

Substance that accepts hydrogen ions in water

Question 42

Buffer

Answer 42

Keeps a solution within a consistent range of pH

Question 43

How does a buffer maintain as consistent pH?

Answer 43

Alternately donating and accepting ions that contribute to pH