Atoms, Molecules, and Ions

Question 1

Dalton’s Atomic Theory

Answer 1

Set of postulates that established the fundamental properties of atoms

Question 2

Law of Definite Proportions (Law of Constant Composition)

Answer 2

All samples of a pure compound contain the same elements in the same proportions by mass

Question 3

Law of Multiple Proportions

Answer 3

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

Question 4

Electron

Answer 4

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

Question 5

Alpha Particles

Answer 5

Positively charged particle consisting of two protons and two neutrons

Question 6

Nucleus

Answer 6

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

Question 7

Proton

Answer 7

Positively charged, subatomic particle located in the nucleus

Question 8

Isotopes

Answer 8

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

Question 9

Neutrons

Answer 9

Uncharged, subatomic particle located in the nucleus

Question 10

Atomic Mass Unit (amu, Unified Atomic Mass Unit, u, or Dalton, Da)

Answer 10

Unit of mass equal to 1/12 of the mass of a ^12C atom

Question 11

Fundamental Unit of Charge (e, Elementary Charge)

Answer 11

Equals the magnitude of the charge of an electron (e) with e=1.602x10^-19 C

Question 12

Atomic Number (Z)

Answer 12

Number of protons in the nucleus of an atom

Question 13

Mass Number (A)

Answer 13

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

Question 14

Ion

Answer 14

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

Question 15

Anion

Answer 15

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

Question 16

Cation

Answer 16

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

Question 17

Chemical Symbol

Answer 17

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

Question 18

Atomic Mass

Answer 18

Average mass of atoms of an element, expressed in amu

Question 19

Molecular Formula

Answer 19

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

Question 20

Structural Formula

Answer 20

Shows the atoms in a molecule and how they are connected

Question 21

Empirical Formula

Answer 21

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

Question 22

Isomers

Answer 22

Compounds with the same chemical formula but different structures

Question 23

Structural Isomers

Answer 23

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

Question 24

Spatial Isomers

Answer 24

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

Question 25

Periodic Law

Answer 25

Properties of the elements are periodic function of their atomic numbers

Question 26

Periodic Table

Answer 26

Table of the elements that places elements with similar chemical properties close together

Question 27

Periods (Series)

Answer 27

Horizontal row of the periodic table

Question 28

Groups

Answer 28

Vertical column of the periodic table

Question 29

Metals

Answer 29

Element that is shiny, malleable, good conductor of heat and electricity

Question 30

Nonmetals

Answer 30

Element that appears dull, poor conductor of heat and electricity

Question 31

Metalloids

Answer 31

Element that conducts head and electricity moderately well, and possesses some properties of metals and some properties of nonmetals

Question 32

Main-Group Elements (Representative Elements)

Answer 32

Element in groups 1, 2, and 13-18

Question 33

Transition Metals

Answer 33

Element in groups 3-12 (more strictly defined, 3-11)

Question 34

Inner Transition Metals

Answer 34

Element in the bottom two rows; if in the first town also called lanthanide, or if in the second row, also called actinide

Question 35

Alkali Metals

Answer 35

Element in group 1

Question 36

Alkaline Earth Metals

Answer 36

Element in group 2

Question 37

Pnictogens

Answer 37

Element in group 15

Question 38

Chalcogens

Answer 38

Element in group 16

Question 39

Halogens

Answer 39

Element in group 17

Question 40

Noble Gases (Inert Gases)

Answer 40

Element in group 18

Question 41

Monatomic Ions

Answer 41

Ion composed of a single atom

Question 42

Polyatomic Ions

Answer 42

Ion composed of more than one atom

Question 43

Oxyanions

Answer 43

Polyatomic anion composed of a central atom bonded to oxygen atoms

Question 44

Ionic Bonds

Answer 44

Electrostatic forces of attraction between the oppositely charged ions of an ionic compound

Question 45

Covalent Bonds

Answer 45

Attractive force between the nuclei of a molecule's atoms and pairs of electrons between the atoms

Question 46

Ionic Compound

Answer 46

Compound composed of cations and anions combined in ratios, yielding an electrically neutral substance

Question 47

Molecular Compounds (Covalent Compounds)

Answer 47

Composed of molecules formed by atoms of two or more different elements

Question 48

Nomenclature

Answer 48

System of rules for naming objects of interest

Question 49

Binary Compounds

Answer 49

Compound containing two different elements

Question 50

Hydrates

Answer 50

Compound containing one or more water molecules bound within its crystals

Question 51

Binary Acid

Answer 51

Compound that contains hydrogen and one other element, bonded in a way that imparts acidic properties to the compound (ability to release H^+ ions when dissolved in water)

Question 52

Oxyacids

Answer 52

Compound that contains hydrogen, oxygen, and one other element, bonded in a way that imparts acidic properties to the compound (ability to release H^+ ions when dissolved in water)