Nature of MatterCNS 8Unit 2

SAVE THESE

SHEETS!

Matter- forms of , Kinetic Theory (particle theory)Changing states of matter, heating curveHeat of fusion, heat of vaprorizationMelting, freezing, boiling pointsChemical and physical propertiesChemical and physical changesLaw of Conservation of MassMixture, compound, elementsCrystallline and amorphous solidsDensity, buoyancy, Archimedes principle

UNIT TWO PREVIEW........

What are the States of Matter?

SolidLiquidGasPlasma

SolidsEvery solid has a definite shape & a definite volume.

Tiny particles in constant motion make up all matter.

This idea is called the kinetic theory of matter.

Particles in a solid are held close together by forces between them. They vibrate, but lack the energy to move out of position.

This is why a solid holds its shape.

Crystalline Solids

In most solids, the particles are arranged in repeating, geometric shapes. We call these shapes crystals.

SALT

SUGAR

SNOWFLAKE CRYSTALS

Noncrystalline Solids

Some materials look like solids, but are not made of crystals. We call these amorphous solids.

Some scientists think we should classify these things as "thick liquids"!

What items are we talking about?

Glass

Plastics

Gels

Liquids

A liquid flows and takes the shape of its container.

Kinetic theory explains the properites of solids and of liquids too!

The particles are close together (like in a solid) but have enough kinetic energy to move over and around each other.

This movement of particles lets a liquid flow and take the shape of the container.

Liquids have a definite size and volume but an irregular shape.

Gases

Gases are "springy", they expand or contract to fill the available space. They can be squeezed into a certain space.

Gases do not have a definite shape or volume.

Plasma

A gas like mixture of positively and negatively charged particles.

The most common form of matter in our universe.

Found in stars and nebula.

Also in fluorescent light.

KINETIC THEORY OF MATTER

All matter is made up of tiny particles that are in constant motion. When energy is absorbed the particles will move faster, and when energy is released the particles will move slower.

Substances can be changed from one state to another.

Particles in matter are held together by attractive forces. As these particles gain energy, the particles move faster and farther apart.

Solids melt...... liquids change to a gas....

Changing States of Matter

When the temperature changes, the state of matter changes.

KINETIC THEORY OF MATTER

All matter is made up of tiny particles that are in constant motion. When energy is absorbed the particles will move faster, and when energy is released the particles will move slower.

Changes in States of Matter

Vaporization-add heat to a liquid until it reaches a temperature at which it changes to bubbles of gas below the surface.

Evaporation- a liquid changes to a gas gradually at temperatures below the boiling point.  

 ex: air drying after swimming ex: air drying wet cement

Condensation- when a gas changes to a liquid. 

 ex: car windows with dew  ex: mirror after a shower

The kinetic theory of matter explains changes of state. The amount of energy needed to change a material from the solid state to a liquid state is the heat of fusion.

Water heat of fusion is 334kJ/kg

Amount of energy needed to change a material from a liquid to a gas is the heat of vaporization.

Water heat of vaporization is 2260kJ/kg

Ice is at -20oC. As the ice is heated, the water molecules gain kinetic energy and move faster. Temp of ice rises to 0 degrees then stops rising. As more heat is added, the motion of the molecules does not increase. Instead the molecules overcome the forces that hold them together in the form of a solid. The molecules move farther apart and the ice melts.

Heat = mass x heat of vaporization

The temperature at which the ice melts is the melting point. Both solid and liquid exist at this temperature.

The amount of heat energy that change a solid to a liquid is call the heat of fusion.

Each substance has a characteristic heat of fusion.

Heat = mass x heat of vaporization

ENERGY

Just as there are many forms of energy, there are different ways to measure these forms. In science, work and energy are commonly measured in joules.

One joule is the amount of energy it takes to lift an object that weighs one Newton a one meter distance. A Newton is the metric unit for weight and is comparable to the weight of a stick of butter. (1 Newton = 0.445 lbs.)

In our everyday lives, other energy measurements are more familiar to us than joules. Some of these measurements include calories, therms, and kilowatt-hours.

It might seem confusing to have so many different measurements for energy. The good news is that one unit can be converted to another.

Energy

Conversions

British

Thermal Unit

Foot-pounds

Joules calories

Kilo-calories

Kilowatt-hours

1 British

Thermal Unit

1 777.9 1055 252.0 0.252 2.93x10-4

1 Foot-pound

0.001285

1 1.356 0.3238 3.238x10-4

3.766x10-7

1 joule 9.481x10-4

0.7376 1 0.2388 2.388x10-4

2.778x10-7

1 calorie

0.003969

3.088 4.187 1 0.001 1.163x10-6

1 kilocalorie

3.969 3088 4187 1000 1 0.001163

1 kilowatt hour

3413 2.655x106

3.6x106

8.598x105

859.8 1

Kinetic Theory of Matter

Safety CheckTie hair back, loose sleeves rolled up.

Understand the procedure. (READ IT AGAIN!)

Check out the equipment. Practice handling new equipment before you begin the experimental work.

Thermometers in the ice water before you start heating. NEVER PUT A THERMOMETER INTO HOT WATER ON AN ALCOHOL BURNER.

Hot water into pail. BE CAREFUL!

GOGGLES ON YOUR FACE, OVER YOUR EYES!

The tare of a container is its weight when it's empty.

To rip a piece of paper into pieces

Tare Tear

1. Balance the triple beam balance.2. Weigh the paper. Record its mass. 3. Take the mass of the paper and ADD IT to the amount of substance that you need.4. Set the balance to the new amount.5. Carefully put the substance onto the paper on the plate of the scale until it balances.

EX: paper = 1g plus 10 g of salt = 11 g total to set on balance.

How to tare......