<< Chapter < Page Chapter >> Page >

Natural sciences

Grade 8

Energy: electricity, heat and light

Module 10

Heat and temperature

Heat is a type of energy – the energy of the movement of particles. Temperature is the measure of how fast the molecules are moving

How do we measure temperature?

We use a thermometer that consists of a glass tube filled with a liquid such as mercury, which expands when it is warmed.

What is absolute zero ?

The lowest temperature possible, at which it becomes impossible for molecules or atoms to move. This occurs at –273,15 ºC or at 0 on the Kelvin scale. This low temperature was measured in a Finnish laboratory.

Find out what the Kelvin scale is.

You probably know that temperature can be measured on a Celsius scale or on a Fahrenheit scale. Temperatures used to be measured in Fahrenheit, so you may still find appliances that are marked in Fahrenheit, but most appliances nowadays use the Celsius scale.

How do you convert Fahrenheit to Celsius?

Subtract 32 and then divide by 9 and multiply by 5

F to C therefore is (-32 ÷ 9 x 5)

For Celsius to Fahrenheit it is:

÷ 5 x 9 + 32

Activity:

To understand temperature conversions [lo 2.4]

Assignment 1:

Do you know the following?

1. The highest temperature ever recorded on earth is 720 million ºF. It was recorded during nuclear fusion, in the USA.

What would this be in ºC?

2. The highest air temperature has been measured in Libya, at 58 ºC.

What is this in ºF?

3. The lowest air temperature was recorded in Antarctica when the thernometer registered –190 ºF.

What is this in ºC?

Try: www.convert-me.com

Assessment of Temperature Conversions

Were you able to do the conversions?

[LO 2.4]

Heat Transfer

Activity:

To determine terms and concepts involved with the transfer of heat [lo 2.1, lo 2.3, lo 2.4]

Assignment 1:

Complete:

There are different terms for describing the transfer of heat:

  • CONVECTION
  • CONDUCTION
  • RADIATION

Assessment of Terms

Were you able to identify the terms?

[LO 2.4]

Heat and Water

Water has a remarkable capacity for retaining heat.

Much energy is needed for the temperature of water to increase or decrease by 1 ºC.

Various factors influence heat retention by water:

  • Water is a liquid.
  • Water is transparent and light beams can penetrate to a depth of 20 m.
  • A mass of water has waves and currents and vertical movement that can distribute heat.

If you compare the heat retention capacity of the land and the oceans, you will realise that there is a considerable difference.

Capacity for heat

We know that heat causes changes in temperature and that a unit of heat is measured in Joule as it is a type of energy.

Specific heat capacity is the amount of heat that is transferred (required or released) when the temperature of a substance changes by 1 ºC or 1 K.

Water is the most expensive substance to heat because great amounts of heat are required to raise the temperature of water by a few degrees. Water, on the other hand, also provides large amounts of heat when it cools down.

The effect of this is most marked in the oceans, as they are large masses of water. They are warmed very slowly, but also retain the heat for a long time.

Questions & Answers

what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Natural sciences grade 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11050/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Natural sciences grade 8' conversation and receive update notifications?

Ask