Atomic Theory

CHEMISTRY FINAL REVIEW

Composition of Matter:

Matter: Anything that has mass + takes up space (everything in the universe)

Types of matter: Atoms (element), molecules (element), compound mixture

Volume: The amount of space that a substance/object occupies

Mass: Amount of matter in an object

Atom: Smallest unit of an element that retains all the properties of that element→cannot be separated

Pure substance: Matter that has uniform and definite composition

Element: A pure substance that is made up of only one type of atom

Compound: A pure substance that is made from 2 or more different elements that are chemically bonded together→the element’s individual properties are completely different from the compound’s properties

Molecule: Two or more atoms chemically combined→can be an element or a compound

Properties: Characteristics/ traits of substances

Extensive: Depends on the amount of matter (volume, mass, weight)

Intensive: Depends on the type of matter (color, boiling point, temperature)

Physical: Observed/measured without changing the chemical identity of the sample (color, length, lust, hardness, volume, opacity)

Chemical: Observed/measured as sample changes chemical identity, “how it will react when it comes in contact with other things” (acidity, reactivity, toxicity, flammability)

Composition: The identity of the substance’s makeup

Mixtures: Two or more pure substances that are physically combined. Each component of the mixture maintains its own identity and many of its properties. They may be separated by physical methods→still behaves the same way

Homogeneous Mixture: Particles distributed uniformly, well mixed→can’t pick things out

Heterogeneous Mixture/Solution: Particles distributed non-uniformly, not mixed well→can pick things out

Changes: When substances change from one to another→chemical reactions

Physical: Matter changes form but not chemical identity→melting ice, choppin wood, shredding wood

“Phase (solid→ liquid, gas→liquid) changes are physical changes”

Chemical: A chemical reaction occurs + new products are formed→burning wood, firework, rotting banana, iron rusting, metabolism

Evidence of Chemical Change→ a new color appears, bubbles of gas are formed, the change is difficult/impossible to reverse, heat, light, or sound is given off (or absorbed), a solid material forms in a liquid (precipitate)

States of Matter:

Liquid:

Definite shape

Not definite volume

Can be compressed

Large intermolecular space

Particles flow

Solid:

Particles are packed closely together

Definite shape + volume

Cannot flow

Cannot be compressed

Less intermolecular space

Particles only vibrate

Gas:

Doesn’t have definite volume or shape

Takes the shape of its container

Particles move freely + fast

Large intermolecular space

Units:

Value: Quantitative description that includes both a unit and a number

Units: Quantities defined by standard that people use to compare one event or object to another→indicates the nature of the measurement

Ex: 100 meters

100: # of units

Meters: Unit by which the distance is measured

SI of Measurements: Metric System

7 Base Units (cannot be split into measurements)

Length: meter (m)

Mass: kilogram (kg)

Time: second (s)

Temperature: kelvin (k)

Electric current: ampere (A)

Luminosity: candela (cd)

Quantity of Matter: moles (mol)

Volume is measured in:

dm3→ 1L

cm3→ 1mL (volume)/1g (mass)

Name:

Symbol:

Scientific Notation:

Tera

Tm

1012

Giga

Gm

109

Mega

Mm

106

Kilo

km

103

Hecto

hm

102

Deca

Dm/da

101

BASE

m

100

Deci

dm

10-1 = 0.1

Centi

cm

10-2

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