Ch 2: Atoms, ions, and molecules

Question 1

radioactivity

Answer 1

spontaneous emission of high energy radiation and particles by materials

Question 2

Subatomic particles

Answer 2

smallest particles of matter

Question 3

Cathode rays

Answer 3

• streams of electrons emitted by the cathode in a partially evacuated tube
• invisible to naked eye

Question 4

Electrons

Answer 4

• fundamental particles present in all forms of matter
• in cathode rays
• negative charge, small mass

Question 5

Beta particles

Answer 5

• radioactive emission equivalent to a high energy electron
• penetrate solid matter better than alpha particles
• charge of 1-

Question 6

alpha particle

Answer 6

• radioactive emission with a charge of 2+
• mass equivalent to that of a helium nucleus
• more massive than B particles

Question 7

Nucleus

Answer 7

positively charged center of an atom contains nearly all of atom’s mass

Question 8

Protons

Answer 8

• hydrogen nuclei

- positively charged subatomic particle present in the nucleus of an atom

Question 9

Neutrons

Answer 9

electrically neutral subatomic particle present in the nucleus of an atom

Question 10

atomic mass unit

Answer 10

• express relative masses of atoms an subatomic particles

- 1/12 the mass of one atom of C with 6 p and 6 n in its nucleus

Question 11

Daltons

Answer 11

unit of mass identical to 1 atomic mass unit

Question 12

atomic theory (Dalton)

Answer 12

• each element consists of tiny indestructible particles, atoms
• all atoms of an element are identical, and are diff from atoms in any other kind of element
• atoms combine in simple ratio of whole numbers to form compounds
• atoms are not changed, created, destroyed, in chemical reactions

Question 13

Isotopes

Answer 13

-atoms of an element containing diff #s of neutrons

Question 14

Nucleons

Answer 14

either a proton or neutron in a nucleus

Question 15

Nuclide

Answer 15

an atom w. a specific combo of n and p

Question 16

Average atomic mass

Answer 16

• a weighted average of the masses of all the isotopes of an element
• calculated by multiplying the natural abundance of each isotope by its mass in atomic ma units then summing the product
• formula: mx=a1m1+a2m2+a3m3+……

Question 17

Natural abundance

Answer 17

• proportion of a particular isotope
• expressed as a %
• relative to all isotopes that element in a natural sample

Question 18

period

Answer 18

horizontal row in the periodic table

Question 19

group (family)

Answer 19

all elements in the same column of the periodic table

Question 20

Metals

Answer 20

• left side of the pt
• -conduct heat and electricity well
• malleable and ductile
• solid at room temp

Question 21

metalloids

Answer 21

• elements along the border between metals and nonmetals , have both non and met properties
• have physical properties of metals
• chemical properties of non mentals

Question 22

non metals

Answer 22

• poor conductors of heat and electricity
• many are gases at room temp
• brittle

Question 23

law of multiple proportions

Answer 23

when 2 masses of one element react w a given mass of another element to form 2 diff compounds, the 2 masses of the first element have a ratio of 2 small whole numbers

Question 24

molecular compound

Answer 24

compound composed of molecules that contain the atoms of 2 or more elements

Question 25

covalent bonds

Answer 25

bond between 2 atoms created by haring one or more pairs of electrons

Question 26

molecular formula

Answer 26

notation showing the # and type of atoms present in one molecule of a molecular compound

Question 27

ionic compound

Answer 27

compound composed of negatively and positively charged ions held together by electrostatic attraction

Question 28

Empirical formula

Answer 28

formula showing the smallest whole number ratio of the elements in a compound

Question 29

formula unit

Answer 29

the smallest electrically neutral unit of an ionic compound

Question 30

polyatomic ions

Answer 30

ions consist of 2 or more atoms joined by covalent bonds

Question 31

Oxoanions

Answer 31

Polyatomic ions containing oxygen and 1 or more other elements

Question 32

Acids

Answer 32

compounds that release hydrogen ions when they dissolve in water

Question 33

Organic compounds

Answer 33

composed of molecules that always contain carbon atoms, hydrogen atoms, and heteroatom

Question 34

Heteroatoms

Answer 34

Oxygen, Nitrogen, Sulfur, Phosphorus, and the halogens < the study of these compounds is organic chemistry

Question 35

Hydrocarbons

Answer 35

organic compounds that contain no heteroatoms bc their molecules only contain hydrogen and carbon atoms

Question 36

Classes of hydrocarbons

Answer 36

Alkanes: all bonds are single Alkene: 1 or > C-C double bonds Alkyne: a hydrocarbon containing 1 or > C-C triple bonds

Question 37

Alcohol

Answer 37

organic compound containing the OH functional group

Question 38

functional group

Answer 38

group of atoms in the molecular structure of a compound has significant impact on the physical and chemical properties of the compound

Question 39

Quarks

Answer 39

elementary particles that combine to form neutrons and protons

Question 40

Nucleosynthesis

Answer 40

The natural formation of nuclei as a result of fusion and other nuclear processes.

Question 41

smallest subatomic particles

Answer 41

electrons and quarks.

Question 42

Neutron Capture

Answer 42

absorption of a neutron by a nucleus

Question 43

Beta decay

Answer 43

spontaneous process by which a neutron in a radioactive nuclide is transformed into a proton and emits a high energy electron (beta particle)