Chapter 4;The Chemical Basis of Life

Question 0

Element

Answer 0

Pure substance that cannot be broken down into other substances by chemical/physical means

Question 1

Matter

Answer 1

Anything that occupies space and had mass

Question 2

Trace element

Answer 2

Element critical to health that makes up less than .01% of body mass

Question 3

Compound

Answer 3

Substance containing two or more elements chemically combined in a fixed ratio

Question 4

Atom

Answer 4

Smallest particle of an element

Question 5

Proton

Answer 5

Subatomic particle with a single unit of positive electric charge

Question 6

Electron

Answer 6

Subatomic particle with a single unit of negative electric charge

Question 7

Neutron

Answer 7

Subatomic particle that has no charge

Question 8

Nucleus (in an atom)

Answer 8

Central core of an atom, contains protons and neutrons

Question 9

Chemical reactivity

Answer 9

Tendency to undergo chemical changes

Question 10

Ionic bond

Answer 10

Chemical bond that occurs when an atom transfers electrons to another atom

Question 11

Ion

Answer 11

Atom that has become electrically charged as a result of gaining or losing electrons

Question 12

Covalent bond

Answer 12

Chemical bond that forms when two atoms share electrons

Question 13

Molecule

Answer 13

Two or more atoms held together by covalent bonds

Question 14

Chemical reaction

Answer 14

The breaking of old and formation of new chemical bonds that result in new substances

Question 15

Reactant

Answer 15

Starting material for chemical reaction

Question 16

Product

Answer 16

Material created as the result of a chemical reaction

Question 17

Polar molecule

Answer 17

Molecule in which opposite ends have opposite electric charges

Question 18

Hydrogen bond

Answer 18

Bond created by the weak attraction of a slightly positive hydrogen atom to a slightly negative portion of another molecule

Question 19

Cohesion

Answer 19

Tendency of molecules of the same kind to stick to one another

Question 20

Adhesion

Answer 20

Attraction between unlike molecules

Question 21

Thermal energy

Answer 21

Total amount of energy associated with the random movement of atoms and molecules in a sample of matter

Question 22

Acid

Answer 22

Compound that donates H+ ions to an aqueous solution and measures less than seven on the pH scale

Question 23

Base

Answer 23

Compounds that removes H+ ions from an aqueous solution and that measures more than seven on the pH scale

Question 24

pH scale

Answer 24

A range of numbers used to describe how acidic or basic a solution is (0-14)

Question 25

Buffer

Answer 25

Something that prevents the pH level from changing dramatically