chemistry semester test

Question 1

in an experiment, the standard that is used for comparison

Answer 1

control

Question 2

in an experiment, the variable whose value depends on the independent variable

Answer 2

dependent variable

Question 3

a set of controlled observations that test a hypothesis

Answer 3

experiment

Question 4

in an experiment, the variable that the experimenter plans to change

Answer 4

independent variable

Question 5

information describes color, odor, shape, or some other physical characteristics

Answer 5

Qualitative data

Question 6

numerical information, describes how much, how little, how big, how tall, or how fast

Answer 6

Quantitative data

Question 7

the amount of mass per unit volume; a physical property

Answer 7

density

Question 8

a systematic approach to problem solving that uses conversation factors to move from one unit to another

Answer 8

dimensional analysis

Question 9

expresses any number as a number between 1 and 10 (known as a coefficient) multiplied by 10 raised to a power (known as an exponent)

Answer 9

scientific notation

Question 10

the number of all known digits reported in measurements plus one estimated digit

Answer 10

Significant figure (or digit)

Question 11

the ability or inability of a substance to combine with or change into one or more new substances

Answer 11

chemical property

Question 12

a characteristic of matter that can be observed or measured without changing the sample’s composition– for example, density, color, taste, hardness, and melting point

Answer 12

physical property

Question 13

a process involving one or more substances changing into new substances; also called a chemical reaction

Answer 13

chemical change

Question 14

states that mass is neither created nor destroyed during a chemical reaction but is conserved

Answer 14

law of conservation of mass

Question 15

a transition of matter from one state to another

Answer 15

phase change

Question 16

a type of change that alters the physical properties of a substance but does not change its composition

Answer 16

physical change

Question 17

a percentage determined by the ratio of the mass of each element to the total mass of the compound

Answer 17

percent by mass

Question 18

a chart that organizes all known elements into a grid of horizontal rows (periods) and vertical columns (group or families) arranged by increasing atomic number

Answer 18

periodic table

Question 19

the smallest particle of an element that retains all the properties of that element; is electrically neutral, spherically shaped, and composed electrons, protons, and neutrons

Answer 19

atom

Question 20

a negatively charged, fast-moving particle with an extremely small mass that is found in all forms of matter and moves through the empty space surrounding an atom’s nucleus

Answer 20

electron

Question 21

a subatomic particle in an atom’s nucleus that has a positive charge of 1+

Answer 21

proton

Question 22

a neutral, subatomic particle is an atom’s nucleus that has a mass nearly equal to that of a proton

Answer 22

neutron

Question 23

The extremely small, positively charged, dense center of an atom that contains positively charged protons and neutral neutrons

Answer 23

nucleus

Question 24

the weighted average mass of the isotopes of that element

Answer 24

atomic mass

Question 25

the number of protons in an atom

Answer 25

atomic number

Question 26

atoms of the same element with different numbers of neutrons

Answer 26

isotope

Question 27

states that each electron occupies the lowest energy orbital available

Answer 27

aufbau principle

Question 28

the arrangement of electrons in an atom, which is prescribed by three rules--- the Aufbau Principle, the Pauli exclusion principle ,and Hund’s rule

Answer 28

electron configuration

Question 29

Consists of an element’s symbol, representing the atomic nucleus and inner-level electrons, that is surrounded by sots, representing the atom’s valence electrons

Answer 29

electron-dot structure (lewis structure)

Question 30

states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals

Answer 30

Hund's rule

Question 31

States that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins

Answer 31

pauli exclusion principle

Question 32

the electrons in an atom’s outermost orbitals; determine the chemical properties if an element

Answer 32

Valence electrons

Question 33

in the periodic table, the f-block elements from period 7 that follow the element actinium

Answer 33

actinide series

Question 34

Group 1 elements, except for hydrogen, they are reactive and usually exist as compounds with other elements

Answer 34

alkali metals

Question 35

group 2 elements in the modern periodic table and are highly reactive

Answer 35

alkaline earth metals

Question 36

a vertical column of elements in the periodic table arranged in order of increasing atomic number; also called a family

Answer 36

Group

Question 37

a highly reactive group 17 element

Answer 37

halogens

Question 38

in the periodic table, the f-block elements from period 6 that follow the element lanthanum

Answer 38

lanthanide series

Question 39

an element that is solid at room temperature, a good conductor, of heat and electricity, and generally is shiny; most are ductile and malleable

Answer 39

metal

Question 40

an element that has physical and chemical properties of both metals and nonmetals

Answer 40

metalloid

Question 41

an extremely unreactive group 18 element

Answer 41

noble gas

Question 42

elements that are generally gasses or dull, brittle solids that are poor conductors of heat and electricity

Answer 42

nonmetal

Question 43

a horizontal row of elements in the modern periodic table

Answer 43

period

Question 44

an element in groups 3-12 that is contained in the d-block of the periodic table, and with some exceptions, is characterized by a filled d orbitals of energy level n-1

Answer 44

transitional metal

Question 45

an atom or bonded group of atoms with a positive or negative charge

Answer 45

ion

Question 46

states that atoms lose, gain, or share electrons in order to acquire the stable electron configuration of a noble gas

Answer 46

octet rule