Natural Science Test unit 4: Thursday, 24th May

What do you have to know? 

• Definition of energy: Energy is the ability to do work. Energy can´t be created or destroyed, it can only be transformed. 
• Forms of energy: Mechanical (kinetic or potential), chemical, thermal, light, electrical, nuclear. You have to know examples and definition of these forms of energy. 
• Common energy transformations: Cars and other means of transport (chemical- into kinetic and thermal), electric drills (electrizal- into thermal, light and kinetic), solar panels (light- into electrical) or food (calories). 
• Sources of energy: Renewable (they are not limited) like hydrolectric, wind, solar or biofuels. And non-renewable (they are limited) like petroleum, natural gas, coal or uranium. You have to explain these sources.
• Environment: Explain the problems that the non-renewable sources cause to the environment (acid rain, global warming, pollution). What are the three Rs? Explain them and give examples. 

This video is long, but it´s perfect to review all the contents.