Chem Exam

independent variable

a variable (often denoted by x ) Which is changed by the experimenter.

dependent variable

a variable (often denoted by y ) whose value depends on that of another variable.

control variable

a factor in an experiment that remains constant

Scatter Plot Graph

A graph of plotted points that show the relationship between two sets of data that do not depend on each other where the line is not connected. (Ex. height versus weight)

Bar Graph (Histogram)

compares values across categories

alchemy

medieval chemical philosophy based on changing metal into gold; a seemingly magical power or process of transmutation

transmutation

the conversion of an atom of one element to an atom of another element

copper

Cu 29

Silver

Ag 47

Gold

Au 79

zinc

Zn 30

Brass

An alloy of copper and zinc.

alloy

A mixture of two or more metals

tin

Sn 50

bronze

an alloy of copper and tin

ore

Rock that contains a metal or useful mineral.

Smelting

The process by which ore is melted to separate the useful metal from other elements.

iron

Fe 26

steel

an alloy of iron and carbon

alkali metals

Group 1

alkaline earth metals

Group 2

transition metals

Group 3-12 elements

Post Transition Metals

the metals on the left side of the staircase. Not very reactive.

Metaloids

(semiconductors) are the elements that have the properties of both metals and nonmetals

noble gasses

unreactive gasses

reactive nonmetals

halogens and others

Lanthanoids

Elements 57-71

Actinoids

Elements 89-103

family on periodic table

sections of elements with similar properties

group on periodic table

vertical columns with similar propities

periods on periodic table

A horizontal row of elements in the periodic table

periodic

describes something that occurs or repeats at regular intervals

atomic number

the number of protons in the nucleus of an atom the top whole number on the ptable

atomic mass

the average weight of an element (protons + neutrons) the bottom number on the ptable

precipitate

a solid that forms and settles out of a liquid mixture

Oxidation

A chemical change in which a substance combines with oxygen, rust or tarnish inside of handwarmers

Luster

the way a metal refelcts light (shiny)

malleable

flexible; can be shaped

molar mass

the mass in grams of one mole of a substance

mole

unit used to measure the amount of a substance

gram

unit of mass

AMU

atomic mass unit

exothermic reaction

A reaction that releases energy in the form of heat

inside of handwarmers

graduated cylinder

used to measure the volume of a liquid

Beaker

used to hold solids or liquids, not used for measuring

erlenmeyer flask

used to hold liquids, has narrow neck to prevent splashes

Distilled water

water that has been purified by distilation

sample jar

stores solids or liquids

test tube

open tube used to hold liquid

dropper bottle

used to dispense small amount of liquid

electronic balance (scale)

used to measure mass (weight)

weighing dish

holds solids while weighing

bunsen burner

used to heat substances with natural gasses

crucible tongs

used to pick up and hold hot items

hotplate

used for heating with electricity

watch glass

Used as a cover for beakers

funnel

a device used for pouring a liquid into a narrow opening etc.

filter paper

special paper used to separate solids from liquids

test tube rack

Holds test tubes

mortar and pestle

to grind chemicals to a powder

crucible

a dish used to cook chemicals by fire

ring stand and ring

Holds items over flame for a long period of time or filtering

ceramic triangle

A triangular shaped device that can be placed on an iron ring to hold a crucible

well plate

a flat plate with multiple "wells" used as small test tubes