The document defines six main forms of energy: light, chemical, sound, kinetic, electrical, and thermal. It discusses renewable energy sources like solar, wind, water, biomass, and geothermal energy. Non-renewable sources covered are fossil fuels like coal, oil, and natural gas. Nuclear energy from uranium is also discussed. The text then explains electricity, different types of charges, conductors and insulators. It concludes with a brief overview of magnetism and magnetic poles.

1.
Provincia
Marista
Mediterránea
Colegio
“La
Sagrada
Familia”
UNIT 8: ENERGY
- gives us light, sound and heat.
Energy - makes things move.
- powers machine.
- most of it comes from the Sun.
Six forms: - natural sources (stars) or artificial (light bulbs and torches).
- fastest form of energy (300.000 km/s).
*LIGHT - made up of seven different colours.
- it allows us to see shapes, colours and sizes.
- it always travels in a straight line.
(exepction  light can be absorbed, reflected or refracted.
- released when a chemical reaction occurs.
*CHEMICAL - car burns petrol  chemical reaction  chemical energy
transformed into kinetic energy.
- more examples: batteries and food.
- is a vibration that can travel in any direction from the source.
- large vibrations loud sounds.
*SOUND - smal vibrations  soft sounds.
- can travel through gases, liquids, solids but not through vaccum.
- all moving things have it.
*KINETIC - the heavier and obtejct is, the faster it moves and the more kinetic
energy it has.
- E.g.: moving car, windsurfer, bike in movement.
- used to power machines.
*ELECTRICAL - can be transformed into light, sound, heat and movement.
- sources: burning fossil fuels/ sunlight, wind, water and biomass/
nuclear power stations.
- it flows from a warm substance to a cooler substance.
(this flow is called heat)
*THERMAL
- sources: the Sun/fossil fuels (warm our houses, cook food)

2.
Provincia
Marista
Mediterránea
Colegio
“La
Sagrada
Familia”
UNIT 8: ENERGY
RENEWABLE ENERGY SOURCES (can be replaced)
- doesn´t pollute.
*SOLAR EN.
- solar panels are used.
- clean.
*WIND EN. - only in windy places.
- wind turbines are used - can damage habitats.
- can kill birds.
- doesn´t pollute.
*WATER EN. -damage habitats.
- dams
- cause biodiversity loss.
- organic material derived from living things (wood, dried vegetation, food
waste)
*BIOMASS - biomass is burned  steam produced turns a turbine  electricity.
- causes air pollution.
- heat produced by the decomposition of underground radioactive
substances
*GEOTHERMAL EN. - doesn´t pollute.
- limited to certain geographic areas.

3.
Provincia
Marista
Mediterránea
Colegio
“La
Sagrada
Familia”
UNIT 8: ENERGY
NON-RENEWABLE ENERGY SOURCES (limited)
*FOSSIL FUELS: decomposed organic material that has been deep underground for millions
of years.
- pollutes.
- COAL
- produces lots of energy.
- oil spills can cause ecological disasters.
- OIL
- easy to transport and store
- NATURAL GAS
- nuclear power stations use a radioactive metal to generate electricity.
*URANIUM - we have enough to generate electricity for many centuries.
are expensive.
- stations
produce radioactive waste products (can cause cancer).

4.
Provincia
Marista
Mediterránea
Colegio
“La
Sagrada
Familia”
UNIT 8: ENERGY
ELECTRICITY
Objects have electrical charges. They can be positive or negative charges.
- conductors (copper, aluminium).
Materials can be electrical
- insulators (wood, rubber, cotton, plastic).
- current  it´s when an electrical charge moves (flow) in an
electrical conductor.
Two types of electricity
- static  it´s a form of electricity that doesn´t flow (lightning,
hair after brushing it)
MAGNETISM
A magnet is an object which can attract certain metals (iron, steel…). They can be natural
(magnetite) or man-made.
Magnets have two poles: north pole and south pole.
N&N
repel S&N  attract
S&S