Review for Science Final.
Electromagnetic Waves Energy is not a substance that has mass and volume. We know that energy exists because of its effect on matter (the things around us). Light is a form of electromagnetic energy and creates vibrations in the form of waves..
Physical Properties of Matter Physical properties can be observed without changing the identity of the substance: -Color - Smell - Hardness - Luster - Phases of matter (solid/liquid/gas)
Physical Properties of Matter Mass – the amount of matter in an object If the ice melts, is there still the same amount of mass in the glass?.
Physical Properties of Matter Volume – the amount of space taken up by an object. - mL for liquids - cm³ for solids.
Physical Properties of Matter Density – the amount of mass in a certain volume of material. -Find the mass -Find the volume -Divide the mass by the volume Density (g/cm³) = mass (g) volume (cm³) What instruments could be used to find the density of the cube?
Physical Properties of Matter Density of liquids: Some liquids float on others forming layers. Which is denser, karo syrup or vegetable oil?.
Physical Changes A physical change is a change in size, shape or state without forming a new substance.
Physical Changes State of matter: Add heat: particles move faster and spread apart - solid > liquid > gas Take away heat: particles slow down and move closer together - solid < liquid < gas
Elements and Atoms An element is a substance that cannot be broken down any further into anything simpler. Atoms are the smallest particle of an element that have the same chemical properties as the element.
Chemical Changes A chemical change is a change in matter that produces a new substance with different properties from the original. Rust is iron oxide: iron + oxygen = rust.
Chemical Changes A compound is a chemical combination of two or more substances. Sugar is composed of the elements: carbon, hydrogen and oxygen C 12 H 22 O 11 Carbonic acid is also composed of the elements: carbon, hydrogen and oxygen
DO NOW Which of the following graphs shows how the temperatures of the two cups of water most likely changed over 30 minutes?.
Temperature and Heat: Energy Energy = the ability to move matter Any moving object has energy – Molecules – Cars – Balls – Bikes – A swung baseball bat
Moving Molecules Produce Heat Molecules move The average kinetic energy determines how hot or cold a material is…its temperature..
Two Kinds of energy: Kinetic and Potential.
Kinetic Energy The energy of any moving object – A speeding roller coaster dropping down a hill.
Potential Energy Energy stored in an object or material. – Moving an object upwards against gravity. A roller coaster climbing up to the next drop.
Potential Energy and Kinetic Energy
Heat Energy flows between two objects because they have different temperatures. Heat is a form of energy. Energy will flow from a hotter object to a cooler one and continue to flow until the objects are the same temperature..
Radiation, Conduction and Convection Radiation – The transfer of energy by electromagnetic waves. Conduction – The movement of energy through direct contact. Convection – The transfer of energy by the flow of a liquid or gas..
Electricity and Magnetism Static Electricity: when electrons move from one place to another and cause a buildup of an electrical charge.
Electricity and Magnetism Conductor: A material through which electricity flows easily - metals, water, humans Insulator: A material through which heat or electricity does not flow easily – rubber, wood, plastic
Electricity and Magnetism Open circuit: a circuit that has a gap, so electrons cannot flow. Close circuit: a circuit that has no gap, so electrons can flow.
Electricity and Magnetism Magnet: any object that attracts or repels other magnets, and also attracts metal objects made of iron, cobalt or nickel.
Speed and Distance Average speed = distance ÷ time 3000 m ÷ 15 min = 200m/min.