Zusammenfassung der Ressource
Energy transfers
- States of matter
- What is matter?
- Anything that is made up
of Atoms and molecules
- Particle theory
- Solid
- Particles close together
- Liquid
- Particles further apart
- Gas
- Particles
really far apart
- Melting
- The heat energy
from the Bunsen
burner is transferred
to the particles as
kinetic energy,
which causes them
to vibrate away from
each other
- Evaporating
- Further energy being transferred
causes the particles to fly really far
apart from each other, making a gas
- Condensing
- As the kinetic energy
is lost, the particles
cool and slow down
to come back
together as a liquid
- Freezing
- As the particles
become completely
still, they form a solid
- Conduction and convection
- A thermal conductor is a material that transfers heat easily
- A thermal
insulator is
a material
that does
not, e.g. air
- Conduction
- Conduction is one of the ways that heat can be
transferred, and only really happens in solids
- Why is metal a good conductor?
- The outer electrons
of metal atoms drift,
and are free to move
- Radiation
- All objects emit (give out) and
absorb (take in) infrared radiation.
- The hotter an object, the
more infrared radiation it
radiates in a given time.
- Matte surfaces
emit more radiation
than shiny surfaces.
- Dark surfaces
emit more infrared
radiation than light
surfaces at the
same
temperature.
- Objects which have larger
surface areas emit more
infrared radiation than
objects with smaller surface
areas.
- Calculating energy efficiency
- Joules
- Energy is measured in Joules
- Joules per second (J/s) shows us
how much energy is used over time
- 1 Joule per sec = 1 watt
- Watt Hours
- A 100w light bulb on for
1 hour will use 100 watt
hours (wh) of electricity
- Or 0.1 kilowatt hours (kwh
- On an electricity bill, 1 unit
of energy = 1 kilowatt hour