Ch2: Atoms, Molecules, and Ions

Question 0

Alkanes

Answer 0

Compounds of carbon and hydrogen containing only carbon-carbon single bonds.

Question 1

Alcohol

Answer 1

An organic compound obtained by substituting a hydroxyl group (-OH) for a hydrogen on a hydrocarbon.

Question 2

Angstrom

Answer 2

A common non-SI unit of length, denoted A, that is used to measure atomic dimensions: 1A =10^-10 m.

Question 3

Anion

Answer 3

A negatively charged ion.

Question 4

Atomic Mass Unit (amu)

Answer 4

A unit based on the value of exactly 12 amu for the mass of the isotope of carbon that has six protons and six neutrons in the nucleus.

Question 5

Atomic number

Answer 5

The number of protons in the nucleus of an atom of an element.

Question 6

Atomic weight

Answer 6

The average mass of the atoms of an element in atomic mass unit (amu); it is numerically equal to the mass in grams of one mole of the element.

Question 7

Cathode Rays

Answer 7

Streams of electrons that are produced when a high voltage is applied to electrodes in an evacuated tube.

Question 8

Cation

Answer 8

A positively charged ion.

Question 9

Chemical formula

Answer 9

A notation that uses chemical symbols with numerical subscripts to convey the relative proportions of atoms it the different elements in a substance.

Question 10

Chemical nomenclature

Answer 10

The rules used in naming substances.

Question 11

Electron

Answer 11

A negatively charged subatomic particle found outside the atomic nucleus; it is a part is all atoms. An electron has a mass of 1/1836 times that of a proton.

Question 12

Electronic charge

Answer 12

The negative charge carried by an electron; it has a magnitude of 1.602 X 10^-19 C.

Question 13

Empirical formula

Answer 13

A chemical formula that shows the kinds of atoms and their relative numbers in a substance in the smallest possible whole-number ratios.

Question 14

Group (periodic table)

Answer 14

Elements that are in the same column of the periodic table; elements within the same group or family exhibit similarities in their chemical behavior.

Question 15

Hydrocarbons

Answer 15

Compounds composed of only hydrogen and carbon.

Question 16

Ion

Answer 16

Electrically charged atom or group of atoms (polyatomic ion); ions can be positively or negatively charged, depending on whether electrons are lost (positive) or gained (negative) by the atom.

Question 17

Ionic compound

Answer 17

A compound composed of cations and anions.

Question 18

Isomers

Answer 18

Compounds whose molecules have the same overall composition but different structures.

Question 19

Isotopes

Answer 19

Atoms of the same element containing different numbers of neutrons and therefore having different masses.

Question 20

Mass Number

Answer 20

The sum of the number of protons and neutrons in the nucleus of a particular atom.

Question 21

Mass Spectrometer

Answer 21

An instrument used to measure the precise masses and relative amounts of atomic and molecular ions.

Question 22

Metalloids

Answer 22

Elements that lie along the diagonal line separating the metals from the nonmetals in the periodic table; the properties of metalloids are intermediate between those of metals and nonmetals.

Question 23

Molecular compound

Answer 23

A compound that consists of molecules.

Question 24

Molecular Formula

Answer 24

A chemical formula that indicates the actual number of atoms of each element in one molecule of a substance.

Question 25

Neutron

Answer 25

An electrically neutral particle found in the nucleus of an atom; it has approximately the same mass of a proton.

Question 26

Nonmetal elements (nonmetals)

Answer 26

Elements in the upper right corner of the periodic table; nonmetals differ from metals in their physical and chemical properties.

Question 27

Nuclear model

Answer 27

Model of an atom with a nucleus containing protons and neutrons and with electrons in the space outside the nucleus.

Question 28

Nucleus

Answer 28

The very small, very dense, positive charged portion of an atom; it is composed of protons and neutrons.

Question 29

Organic chemistry

Answer 29

The study of carbon-containing compounds, topically containing carbon-carbon bonds.

Question 30

Oxyanion

Answer 30

A polyatomic anion that contains one or more oxygen atoms.

Question 31

Period (periodic table)

Answer 31

The row of elements that lie in a horizontal row in the periodic table.

Question 32

Periodic Table

Answer 32

The arrangement of elements in order of increasing atomic number, with elements having similar properties placed in vertical columns.

Question 33

Polyatomic ion

Answer 33

An electrically charged group of two or more atoms.

Question 34

Proton

Answer 34

A positively charged subatomic particle found in the nucleus of an atom.

Question 35

Structural Formula

Answer 35

A formula that shows not only the number and kinds of atoms in the molecule but also the arrangement (connections) of the atoms.

Question 36

Subatomic Particles

Answer 36

Particles such as protons, neutrons, and electrons that are smaller than an atom.