Properties of Matter

Matter- anything that has mass, weight, volume, and density makes up all of the “stuff” in the universe Mass the most important general property of matter (according to Mr. Rhodes)

- the amount of “stuff” in an object - the mass of an object never changes - can also be defined as a measure of inertia “the resistance of an object to changes in its motion” - is usually measured in grams

More gravitational pull Weight - the response of mass to the pull of gravity the greater the mass, the greater its gravitational pull More gravitational pull More Mass More weight

- is measured (scientifically) in Newtons It’s named after me! (note: the gravitational pull of the earth is 9.8N at sea level. To find your scientific weight, simply measure your mass by 9.8)

Volume - the amount of space an object takes up is measured in liters or cubic centimeters (cc or cm3)

Density - the mass per unit of volume In other words… How much stuff is crammed into a given area

density = mass volume d=m/v - can be found using the following formula: density = mass volume the unit for the unit for or d=m/v - is usually measured in g/cm3

- water has a density of 1 g/cm3 Crammed into 1 gram of water 1 cubic centimeter less dense objects will float on more dense objects so, any object with a density of less than 1 g/cm3 will float on water, and an object with a density of more than 1 g/cm3 will sink

Phases of Matter

There are 4 phases of matter: solids liquids gases plasma

1.) solids - matter having a definite shape and volume - molecules are very tightly packed together

these molecules occur in regularly repeating patterns called crystals:

amorphous solids note: sometimes solids do not have a definite shape. These are called amorphous solids and include things like Play-doh wax and

2.) liquids matter having a definite volume, but no definite shape (will take the shape of whatever container it is in) molecules are more loosely packed together, allowing the substance to flow

fluid- any substance that can flow can be either a gas or a a liquid

viscosity- obviously, some liquids are very fluid, and some are not a measure of how well a liquid flows HIGH viscosity LOW viscosity

examples: low viscosity high viscosity water sludge lemonade honey

(note: glass is a very viscous liquid. It is not a solid)

3.) gases - matter having no definite shape and no definite volume (will completely fill whatever container it is in) - molecules tend to be very far apart, allowing them to be very fluid

unlike solids and liquids, the molecules in a gas can be pushed closer together

The Gas Laws many scientists have discovered properties about gases. the three most important are: Robert Boyle Boyle’s Law “the volume of a fixed amount of gas varies inversely with the pressure of the gas” in other words…

That’s Latin for “and the opposite is also true” as the pressure on a gas increases, the volume decreases (and vice versa) vice versa That’s Latin for “and the opposite is also true” ? Boyle’s Law can also be simplified as: P V

Jacques Charles Charles’ Law “the volume of a fixed amount of gas varies directly with the temperature of the gas” in other words…

as the temperature of a gas increases, so will its volume (and vice versa) Charles’ Law can also be simplified as: T V

Amedeo Avogadro Avogadro’s Law “equal volumes of gases at the same pressure and temperature will have the same number of molecules” - the number of molecules is equal to 6.023 X 1023 molecules per liter of gas (602,300,000,000,000,000,000,000,000) - this is called Avogadro’s Number

pressure = force  area Pressure The most important measurements of gases are temperature, volume, and Pressure the amount of force placed on an object per unit of area - caused by the motion of particles - can be found using the formula pressure = force  area

- is measured in pascals (Pa) one pascal equals one Newton of force per square meter Blaise Pascal - most pressures on earth are listed in kilopascals (1,000 pascals) to keep the numbers small atmospheric pressure at sea level on earth equals 101.3 kPa

4.) Plasma - matter made up of molecular pieces contains so much energy that the molecules cannot stay together and break apart - very rare on earth - very common in the rest of the universe

examples of objects in the plasma state include stars lightning

Changes in Matter 2 types:

1. physical changes when the size, shape, and/or appearance of an object changes, but it still remains the same type of matter - examples include wadding up a sheet of paper freezing water and

2. chemical changes when a substance is changed into one or more completely new substances - examples include breaking down water into hydrogen and oxygen burning paper and

Phase Changes - a type of physical change occurs when a substance gains or loses energy - will change the volume of the substance but not the mass! - 5 types: melting, freezing, vaporization, condensation, and sublimation

Melting - the changing of a solid into a liquid - occurs when a solid gains energy - rigid crystal structure breaks down - causes the substance to increase in volume amorphous solids melt faster than crystalline solids do melting point- the temperature at which a solid turns into a liquid

Ice Salt Diamond 32 801 1,500 3,700 6,717 Substance Melting Point (in Celsius) (in Fahrenheit) 32 Ice Salt 801 1,500 Diamond 3,700 6,717

Freezing - the changing of a liquid into a solid - occurs when a liquid loses energy - rigid crystal structure is re-established - causes the substance to decrease in volume freezing point- the temperature at which a liquid turns into a solid THE FREEZING POINT OF A SUBSTANCE IS EXACTLY THE SAME AS ITS MELTING POINT!!!

Vaporization - the changing of a liquid into a gas - occurs when a liquid gains energy - causes the substance to increase in volume there are two types- 1. evaporation- vaporization which occurs on the surface of a liquid

vaporization which occurs inside a liquid 2. boiling- vaporization which occurs inside a liquid bubbles filled with water vapor, NOT AIR! boiling point- the temperature at which a liquid begins to vaporize

Ice Salt Diamond 100 212 1,413 2,575 4,200 7,592 Substance Boiling Point (in Celsius) (in Fahrenheit) 100 212 Ice Salt 1,413 2,575 Diamond 4,200 7,592

more pressure higher boiling point → less pressure → - the boiling point of a substance depends on the surrounding air pressure: more pressure higher boiling point → less pressure → lower boiling point

Denver, CO Seattle, WA the “Mile High City” Elevation- 0 ft Temperature required to boil water- 95oC Temperature required to boil water- 100oC

Condensation - the changing of a gas into a liquid - occurs when a gas loses energy - causes the substance to decrease in volume dew point- the temperature at which a gas turns into a liquid THE DEW POINT OF A SUBSTANCE IS EXACTLY THE SAME AS ITS BOILING POINT!!!

5. Sublimation - when a solid goes directly into a gas, skipping the liquid state completely - requires a high level of energy - examples include mothballs burning wood

and… “dry ice” (frozen carbon dioxide)