heating & cooling Flashcards
(23 cards)
Temperature
how hot or cold something is .
Conduction
one of the ways in which thermal energy is transfer .
How does conduction transfer?
the particles are touching each other and from hotter they become cooler and cooler.
What is Convection ?
When a gas or a liquid gets heated the particles move up.
Why Convection is impossible in a solid ?
because the particles don’t have enough space to move.
An important thing about Convection ?
WARM THINGS ARE LESS DENSE.
What is Radiation?
A transfer of heat through a empty space .
What is Expansion?
When you heated a metal object the thermal energy and this makes the particles vibrate more , as they vibrating it makes more space and it expands . When you put cold water the particles vibrate less .
What is the normal room temperature?
20 degrades
What do you use to measure the temperature ?
For measuring the temperature we use a thermometer.
What about freezing and boiling water ?
The water freezes at 0 degrades and it boils at 100 degrades Celsius.
Absence of thermal energy ?
Cold is the absence of thermal energy .
Infa-red ?
Caries thermal energy from a hotter object to a cooler object .
Changes of state?
The changes of state are boiling , melting , condensing and freezing .
What does convection happen in ?
Gases and liquids .
What happens when you cool a solid?
It contacts because the particles vibrate more and take up more space .
Name the way thermal energy is transferred ?
Conduction
When a material expands does it become more dense or less dense ?
less dense because there are the same number of particles in a larger volume.
Body temperature ?
37 degrades Celsius
What materials are good for thermal insulation ?
Glass , wood and air .
Condensing
When it takes the energy out and from gases turn in to a liquid .
Evaporating
It take energy to evaporate a liquid into a gas.The particles in a gas move faster than the particles in a liquid. This extra energy has to come from somewhere.
Convection currents
When a hot air rises cooler air takes its place .
