MATTER Chapter 2.1. Matter Anything that has mass and occupies space. Chemistry is the study of matter and how it changes.

MATTER

Chapter 2.1Chapter 2.1

Matter

Anything that has Anything that has mass and occupies mass and occupies space.space.

ChemistryChemistry is the study is the study of matter and how it of matter and how it changes.changes.

Pure Substances

Uniform and definite Uniform and definite compositioncomposition

Formed and separated Formed and separated chemicallychemically

2 types Elements & compounds2 types Elements & compounds

Pure Substance

ElementsElements – a substance that cannot be – a substance that cannot be broken down into smaller substances.broken down into smaller substances. AtomsAtoms – smallest particle that has – smallest particle that has

properties of an element. properties of an element. Both expressed by symbolsBoth expressed by symbols

Compounds

CompoundsCompounds – a substance – a substance formed when two or more formed when two or more elements elements chemicallychemically combine combine together.together.

Molecules

The smallest unit of a The smallest unit of a substance that exhibits all of substance that exhibits all of the properties characteristic of the properties characteristic of that substance (compound)that substance (compound)..

Two or more atoms chemically Two or more atoms chemically combinedcombined

Chemical Formulas

Ex. CEx. C1616HH1010NN22OO22

Mixtures

A physical combination of more than one substance.

(Two Types)

Homogeneous Mixtures

SolutionsSame throughout (miscible)

ex: flat soda, salt water, black coffee

Heterogeneous Mixtures

Not uniformly mixed, different parts

Substances that need to be shaken

ex: noodle soup, granite

Classifying Liquid Mixtures:

miscible-dissolve into each other

immiscible-don’t mix into each other. You can see layers

ex: oil and water.

Liquids Mix with Gas

Can you think of a very common example???

MATTER AND ENERGY

2.2

Kinetic Theory

1. All matter is made of atoms and molecules that act like tiny particles.

Kinetic Theory

2.These tiny particles are always in motion. The higher the temperature, the faster the particles move.

Kinetic Theory

3. At the same temperature, heavier particles move slower than lighter particles.

Phases/States of MatterGasGasliquidliquidsolidsolidplasmaplasma

States of Matter - Gases

no definite shape.no definite volume.easy to compress.most random arrangement of particles.

Most spread out.

Gases

Property of gases is called pressure. the force exerted per unit area of a surface

Liquids

Definite volumeno definite shape (takes shape of container)Difficult to compressdisorderly arrangement on particles

Close together

Liquids

Property of Liquids is called viscosity. the resistance of a fluid to flow

Solids

Definite shapeDefinite volumeDifficult to compressOrderly arrangement of particles close together

Smallest amount of movement of particles.

Energy

The ability to change state or move matter.

Changing state does not change composition of the substance

liquid gassolid

Changes of State

Law of conservation of matter (mass)

Matter (mass) cannot be created or destroyed.

It only changes its state or rearranges its atoms.

Law of conservation of energy

Energy cannot be created or destroyed.

It converts from one form to another during chemical or physical changes.

PROPERTIES OF MATTER

2.3

Physical Property

A characteristic of a substance that can be observed or measured without changing the composition of the substance.

Physical Property

Melting and freezing points.Solubility

Dissolving of a solid into a liquid.

Density

Why do some things float while others sink?

Density

mass/volume (D=m/V)UNITS:mass – (g)Volume – (mL) or (cm3)density – (g/mL) or (g/cm3)

Density

Buoyancy-The force with which a more dense fluid pushes a less dense substance upward.

ex. floating ice.

Example

An unknown metal is measured to be 36 grams. What is it’s density if it has a volume of 15.5 cm3?

D=m/v d= 36 g/ 15.5 cm3

D = 2.322 g/cm3

Last point is sig. figs. 2.3 g/cm3

+1+1

+1 +1

+1

Chemical Properties

The way a substance reacts with others to form new substances with different properties.

Chemical Properties

FlamabilityReactivitycorrosion

Physical Changes

A change in the physical form or properties of a substance that occurs without a change in composition.

Chemical Change

A change that occurs when a substance changes composition by forming one or more new substances.

Chemical Change

4 signs:Evolution heat or lightColor changeFormation of gasFormation of a precipitate (solid residue)