PROPERTIES OF MATTER. Matter can exist in four different states:

Post on 25-Dec-2015

223 views 0 download

Tags:

transcript

PROPERTIES OF MATTER

Matter can exist in four different states:

Solid - definite shapedefinite volume

Particles tightly packed

Incompressible

Particles fixed in place

Particles vibrate in place

Expands slightly when heated

Liquid - definite volumeno definite shape

Particles less tightly packed

Virtually incompressible

Particles move pass each other (flow)

Expands when heated (moderate)

Take the shape of their container

Gas - no definite volumeno definite shape

Particles very far apart

Very compressible

Particles move quickly and randomly in all directions

Expands when heated (greatly)

Fills the entire volume of their container

Plasma

High temperatures

Atoms lose electrons

Examples: stars, lightning, auroras, neon signs, florescent bulbs

Produced when gases are heated to extremely high temperatures

temperature increases, the energy increases

motion of the particles increases.

Matter can be described according to its physical properties and/or chemical properties.

A physical property is a characteristic of matter that can be observed or measured without changing the identity of the substance.

Some physical properties are:

State of matter--

Ice, water, water vapor

solid, liquid, gas, plasma

Melting point --

Boiling point --

0° C32° F

100° C212° F

Water

Color --

water is colorless, diamond is colorless,

milk is white,

ruby is red,

Density -- Oil is less dense than water

Hardness --

diamond is hardest,

chalk is softest

Odor --

Water vs rubbing alcohol

Odor --

Substance State Color Melting Boiling

point °C point °C

Oxygen   Colorless -218 -183

Chlorine   Yellow -101 -34

Ethanol   Colorless -117 78

Mercury   Silvery-white -39 357

Bromine   Reddish-brown -7 59

Water   Colorless 0 100

Sulfur   Yellow 115 445

Aluminum   Silver 660 2519

Sodium chloride   White 801 1413

Gold   yellow 1064 2856

Physical Properties of Some Substances

A chemical property is the ability of matter to combine with another substance or to change into another substance.

Iron reacts with oxygen to form rust.

Copper reacts with moist air to form green copper carbonate.

Examples:

Physical and chemical properties can be used to identify a substance.

Diamond or Cubic ZirconiaAlmost colorless with yellow tinge Absolutely colorless

Hardness: 10 Mohs Hardness: 8.5 Mohs

Density: 3.5 g/cm3 Density: 5.5 g/cm3

Melting Point: 3550 °C Melting Point: 2750 °C

 Physical Changes – Matter can undergo a physical change that results in a dramatically different appearance yet leave the composition unchanged.

CHANGES IN MATTER

All changes of state are physical changes.

Evaporation:

Melting: Freezing:

Condensation:

Solid Liquid

Liquid Solid

Gas Liquid

Liquid Gas

Sublimation: Solid Gas

Pounding

Stretching

Bending

Physical Changes –

Physical Changes –

Cutting

Shredding

BreakingPhysical Changes –

Grinding

Crushing

Physical Changes –

Dissolving

Physical Changes –

Chemical Changes – The process that involves one or more substances changing into new substances - - - also called chemical reaction.

CHEMICAL REACTION

reactants products

methane oxygencarbondioxide

water

The new substances formed (products) in the reaction have different compositions and different properties from the original substances (reactants).

CHEMICAL REACTION

Examples of Chemical Changes

Rusting

Tarnishing

Corroding

Exploding

Chemical Changes

Fermenting

Chemical Changes

Rotting/Decomposing

Chemical Changes

Burning

Cooking

Baking

Chemical Changes

Autumn colors

Chemical Changes

• Transfer of energy• Change in color• Production of a gas• Formation of a precipitate.

The following are indications that a chemical change or chemical reaction has occurred:

Transfer of energy -

Temperature change….becomes hot or cold

Produces light

Change in color -

Production of a gas -

Oxidation of copper metal by nitric acid produces nitric oxide (NO) gas which is immediately oxidized in air to form brown nitrogen dioxide (NO2) gas.

Formation of a precipitate - a solid

Silver chromate (Ag2CrO4) is a brown-red monoclinic crystal and is a chemical precursor to modern photography. It can be formed by combining silver nitrate (AgNO3) and potassium chromate (K2CrO4) or sodium chromate (Na2CrO4)

Process of Precipitation, ( silver nitrate and sodium chloride solutions) white percipitate of silver chloride appears where the two solutions meet. Chemical reaction that produces color change. In a double-replacement reaction, the cations and anions of two ionic compunds

exchange to form new compounds

Formation of a precipitate

The chemical reaction between a copper penny and nitric acid. The dissolved copper produces the blue-green solution; the reddish brown gas produced is nitrogen dioxide