Science Chapter 14

Question 1

a group of two or more atoms linked by chemical bonds to form distinct units

Answer 1

molecule

Question 2

a combination of chemical symbols and numbers showing the type and number of atoms in each compound

Answer 2

chemical formula

Question 3

the sum of the atomic masses of all the atoms in a molecule

Answer 3

molecular mass

Question 4

substances composed of atoms of two or more elements bonded together

Answer 4

compounds

Question 5

molecules that have the same molecular formula but different structural formulas

Answer 5

isomer

Question 6

a substance that has the same physical properties throughout and consists of only one type of atom, one type of molecule, or one nonmolecular compound; all pure substances are either elements or compounds

Answer 6

pure substances

Question 7

a substance that has the same physical properties throughout the substance

Answer 7

homogenous

Question 8

three-dimensional representation of a molecule that shows its shape and the position of its atom

Answer 8

molecular model

Question 9

a substance composed of several pure substances that are physically mixed but not chemically united

Answer 9

mixture

Question 10

a homogeneous mixture that exists because of attraction between atoms, molecules, or ions

Answer 10

solution

Question 11

a substance in a solution that is dissolved

Answer 11

solute

Question 12

a substance in a solution that does the dissolving

Answer 12

solvent

Question 13

describes a mixture in which the molecules of the mixed substances are not completely mixed

Answer 13

heterogenous

Question 14

a mixture containing tiny suspended clumps or particles

Answer 14

colloid

Question 15

the appearance of a blue-tinged milky or cloudy effect within a colloid when a light shines through it

Answer 15

tyndall effect

Question 16

a heterogeneous mixture whose particles are large enough that they will settle

Answer 16

suspension

Question 17

an attractive force that links atoms to form molecules and compounds

Answer 17

chemical bond

Question 18

The most important factor affecting how chemical bonds form is the number of ______ in the valence shell of each atom involved.

Answer 18

electrons

Question 19

a chemical bond resulting from the sharing of valence electrons between atoms

Answer 19

covalent bond

Question 20

Covalent bonds typically form between two _______

Answer 20

nonmetals

Question 21

a covalent bond involving an electron

Answer 21

single bond

Question 22

a covalent bond formed by the sharing of two pairs of electrons

Answer 22

double bond

Question 23

a covalent bond in which three pairs of electrons are shared

Answer 23

triple bond

Question 24

a diagram showing the locations of all the atoms and valence electrons in a molecule or ion

Answer 24

lewis structure

Question 25

describes electrons that are part of more than one chemical bond, being shared by more than two atoms

Answer 25

delocalized

Question 26

the property of an element that describes how strongly atoms of that element pull on electrons in chemical bonds

Answer 26

electronegativity

Question 27

a covalent bond in which both atoms share their electrons equally and the electrons are not pulled closer to one atom than to the other

Answer 27

nonpolar bond

Question 28

a covalent bond in which the more electronegative atom pulls the shared electrons toward itself

Answer 28

polar bond

Question 29

a charge less than that of a proton or electron

Answer 29

partial charge

Question 30

a molecule that has opposite partial charges on opposite ends of the molecule; one end of a polar molecule has a negative partial charge, and the other end has a positive partial charge

Answer 30

polar molecule

Question 31

a substance consisting of atoms covalently bonded into a large structure that does not contain a specific number of atoms

Answer 31

covalent network

Question 32

Although covalent networks do not contain a specific number of atoms, they always combine in ____ ratio of elements.

Answer 32

fixed

Question 33

the simplest ratio of atoms in a covalent network

Answer 33

formula unit

Question 34

the mass of a formula unit

Answer 34

formula mass

Question 35

a negative ion

Answer 35

anion

Question 36

a positive ion

Answer 36

cation

Question 37

a bond formed by the attraction between the oppositely charged ions

Answer 37

ionic bond

Question 38

Ionic bonds typically form between a ____ and a ______

Answer 38

metal, nonmetal

Question 39

an ion formed from a group of atoms

Answer 39

polyatomic ion

Question 40

an orderly geometric arrangement consisting of millions or billions of ions all bonded by electrical attraction

Answer 40

ionic crystal

Question 41

the bonding in metals in which valence electrons are shared by all the atoms in the metal

Answer 41

metallic bonding

Question 42

a repeating unit in a crystalline solid arranged in a three-dimensional pattern

Answer 42

unit cell

Question 43

Molecules not arranged in a repeating, orderly pattern are

Answer 43

amorphous solids

Question 44

a chemical reaction that causes thermal energy to be absorbed and stored in the chemical bonds of the products

Answer 44

endothermic reaction