Introduction To Matter

Describing Matter Matter – anything that has mass and takes up space. The “stuff” that makes up everything in the universe. Exists in many shapes, colors, textures and forms. Water, rocks, living things and stars. All forms of matter are made up of tiny particles that are in constant motion. Too small to be seen with the naked eye.

Properties of Matter Properties of matter help you to identify and classify a sample of something. Properties of Matter: Color Texture Odor Luster Transparency Hardness Resistance to breakage Ability to dissolve

Particle Movement Particles are in constant motion but the speed at which the particles move change with temperature. Temperature increases = particle speed increases Temperature decreases = particle speed decreases Particle speed determines whether a substance will be a solid, liquid or gas.

Phases of Matter The 3 principal phases of matter: Solid Liquid Gas (Ice) (Water) (Water Vapor)

Solids Has a definite shape Has a definite volume. Particles are packed closely together in a fixed position. Particles are not motionless but have slight back and forth motions or vibrations.

Liquids Have no definite shape Have a definite volume. Take the shape of the container its in. Have a definite volume. Particles move around one another freely. Viscosity – the resistance of a liquid to flow. High viscosity – flow slowly Molasses Low viscosity – flow quickly Water or Oil

Gases No definite volume No definite shape Takes both the shape and volume of its container. Particles move at high rates of speed in all directions.

Phase Changes To change the phase of a substance, heat must be added or taken away. 100°C 0°C -10°C

Heat Added or Taken Away Phase Changes Phase Change What Occurs Heat Added or Taken Away Example Freezing Liquid to Solid Taken Away Water to Ice Melting Solid to Liquid Added Ice to Water Condensation Gas to Liquid Steam to Water Evaporation Liquid to Gas Water to Steam

Characteristic Properties Properties that hold true for a particular kind of matter regardless of what the sample is. NEVER change and can be used to identify unknown matter. 2 characteristic properties of substances: Boiling point - The temperature at which a liquid boils. Melting point - The temperature at which solids melt.

Boiling Point/Melting Point Can be used to identify substances that otherwise look the same. A clear substance that boils at 100°C: A clear substance that melts at -190°C: Substance Melting Point (°C) Boiling Point Water 100 Chloroform -64 61 Ethanol -117 79 Propane -190 -42 Table Salt 801 1465 Water Propane

Changes in Matter Matter can be changed in two ways: Physically – any time matter undergoes a change in size, shape or phase. With each of these changes you still have the same particles that made up the original product. Chemically – any time a color change takes place, an odor is produced, heat is produced, or a gas is produced. Each of these produces something new and has altered the particle makeup of the substance.

Physical Changes Changes in the state of matter are examples of physical changes. Changes that alter the form of a substance but not its identity. Crushing a can – still a can Tearing paper – just 2 pieces now Adding sugar to iced tea – only dissolved The form or appearance of the substance changed, but the substance itself didn’t.

Chemical Changes Chemical Changes occur when substances combine or break apart to form new substances. Alters both the form and identity of the substance. Turning sugar into caramel Burning wood Applying acid to limestone to produce gas. You CAN NOT get the original substance back once changed.

Physical or Chemical Changes Description Form Changes Identity Physical or Chemical Food digesting in your stomach Burn a match Car rusting Mix lemonade & water Melt an ice cube Tearing a piece of paper Boiling water Crumple aluminum foil into a ball Baking bread Slice a cookie into 4 pieces Drop antacid tablet into water X X C X X C X X C X P X P X P X P X P X X C X P X X C