Vocabulary
Define "transparent".
Transparent is when light pass through the material.
What are the types of light sources?
Natural and artificial sources.
What happen when you light a candle?
When you light a candle, there is a chemical reaction. The candle burns and react with oxygen.
Metals such as _________ and __________ are excellent thermal conductors.
Metals such as copper and aluminium are excellent thermal conductors.
Give an example of something translucent.
A plastic folder.
Evaporation is when a liquid changes to a gas.
Name the types of materials depending on light.
They can be: transparent, translucent and opaque.
What is opaque?
Something is opaque when light can not pass through it.
To find out the temperature of a substance, we use a ______________________.
Thermometer
Give an example of melting.
Butter in a pan.
Define "thermal insulators".
Thermal insulators don't transfer heat very well.
What are the characteristics of light?
Speed, colour and direction.
When does reflection take place?
Reflection occurs when light hits an object and bounces in another direction.
________ _________ do not transfer heat very well.
Thermal insulators do not transfer heat very well.
Give an example of thermal insulators.
Plastic or wollen gloves.
Define "opaque".
Opaque materials are those that don't let light pass through them.
What are the effects of thermal energy?
Melting, evaporation and expansion.
What is the difference between mirrors and lenses?
Mirrors reflect light and lenses refract light.
When light hits an object, some colors are _________ and some are reflected. We only can see the __________ colours.
When light hits an object, some colors are absorbed and some are reflected. We only can see the reflected colours.
Give an example of refraction.
A straw in a glass of water.
What is the speed of light?
300,000 kilometres per second!
Name the primary colors of light.
Red, blue and green.
Explain the two different types of reflection depending on the surface.
In smooth surfaces, the light reflect in one direction.
In rough surfaces, the light reflect in many directions.
The flow of thermal energy is called ________.
The flow of thermal energy is called heat.
Give an example of a thermal conductor.
A fry pan.