CHAPTER 2 Atoms, Molecules, and Ions

Question 1

positively charged particle consisting of two protons and two neutrons

Answer 1

alpha particle(a particle)

Question 2

negatively charged atom or molecule (contains more electrons than protons)

Answer 2

anion

Question 3

average mass of atoms of an element, expressed in amu

Answer 3

atomic mass

Question 4

(also, unified atomic mass unit, u, or Dalton, Da) unit of mass equal to (1/12) of the mass of a 12C atom

Answer 4

atomic mass unit(amu)

Question 5

number of protons in the nucleus of an atom

Answer 5

atomic number(Z)

Question 6

positively charged atom or molecule (contains fewer electrons than protons)

Answer 6

cation

Question 7

one-, two-, or three-letter abbreviation used to represent an element or its atoms

Answer 7

chemical symbol

Question 8

alternative unit equivalent to the atomic mass unit

Answer 8

Dalton (Da)

Question 9

set of postulates that established the fundamental properties of atoms

Answer 9

Dalton’s atomic theory

Question 10

negatively charged, subatomic particle of relatively low mass located outside the nucleus

Answer 10

electron

Question 11

formula showing the composition of a compound given as the simplest whole-number ratio of atoms

Answer 11

empirical formula

Question 12

(also called the elementary charge) equals the magnitude of the charge of an electron (e) with e = 1.602 x 10^-19 C

Answer 12

fundamental unit of charge

Question 13

electrically charged atom or molecule (contains unequal numbers of protons and electrons)

Answer 13

ion

Question 14

compounds with the same chemical formula but different structures

Answer 14

isomers

Question 15

atoms that contain the same number of protons but different numbers of neutrons

Answer 15

isotropes

Question 16

(also, law of definite proportions) all samples of a pure compound contain the same elements in the same proportions by mass

Answer 16

law of constant composition

Question 17

(also, law of constant composition) all samples of a pure compound contain the same elements in the same proportions by mass

Answer 17

law of definite proportions

Question 18

when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small whole numbers

Answer 18

law of multiple proportions

Question 19

sum of the numbers of neutrons and protons in the nucleus of an atom

Answer 19

mass number (A)

Question 20

formula indicating the composition of a molecule of a compound and giving the actual number of atoms of each element in a molecule of the compound

Answer 20

molecular formula

Question 21

uncharged, subatomic particle located in the nucleus

Answer 21

neutron

Question 22

massive, positively charged center of an atom made up of protons and neutrons

Answer 22

nucleus

Question 23

positively charged, subatomic particle located in the nucleus

Answer 23

proton

Question 24

compounds in which the relative orientations of the atoms in space differ

Answer 24

spatial isomers

Question 25

shows the atoms in a molecule and how they are connected

Answer 25

structural formula

Question 26

one of two substances that have the same molecular formula but different physical and chemical properties because their atoms are bonded differently

Answer 26

structural isomer

Question 27

alternative unit equivalent to the atomic mass unit

Answer 27

unified atomic mass unit (u)

Question 28

T(F) = (9/5 * T(C)) + 32

Answer 28

Celsius to Fahrenheit

Question 29

T(C) = (5/9)(T(F) - 32)

Answer 29

Fahrenheit to Celsius