HEAT -POST -3

30 APRIL 2020


HEAT BLOG 3        

   CLASS 7 SCIENCE 

Good morning class.Thank you for logging in, this is the third blog on the chapter HEAT. 

Hope you went through yesterdays concepts and are thorough with them.

IMPORTANT- KINDLY MARK YOUR ATTENDANCE ON THIS BLOG WITH A GREETING. DO NOT FORGET TO MENTION YOUR NAME AND ROLL NUMBER.

You will need : 

A SINGLE LINED NOTEBOOK WHICH IS NEATLY COVERED. MAKE SURE YOU HAVE USED THE INDEX AND WRITTEN TODAY'S DATE.

THE NOTEBOOK WILL BE EVALUATED SO KINDLY MAKE SURE YOU DO ALL YOUR WORK NEATLY.

At the end of this lesson you will be able to 

• Enlist the features of the Celsius scale
• Enlist and explain the different parts of a lab thermometer.
• Explain how to use a lab thermometer

LET'S BEGIN 

A FEW POINTS ABOUT THE CELSIUS SCALE

1. Was designed by Anders Celsius 
2. The lower fixed point (ice point) is taken as 0°C and the upper fixed point (steam point) is taken as 100°C
3. Between 0 and 100, there are 100 equal divisions 
4. Each division corresponds to 1°C 

LABORATORY THERMOMETER

FEATURES: 

1. It has a thick walled glass tube with a bulb at one end

2.  The bulb and a part of the tube are filled with pure, dry mercury.

3. The part above the bulb is marked from - 10 to 110° C
4. It can be used to measure temperatures between 0 C and 100 C

  

How to use a lab thermometer:

1.Find the value of one small division, It may be 1° C or 0.5° C

2. Suspend the thermometer from a stand with a hook.

3. Put tap water into a 100 ml beaker and dip the thermometer into the beaker making sure the bulb is dipped into the water

4. Observe the mercury thread.when it is constant, record it as the temperature of the water.
5.While reading the temperature,your eye should be at the level of the mercury.

ANSWER THE FOLLOWING ORALLY

• Who designed the Celsius scale ?
• What is the upper fixed point on the Celsius scale 
• Practise drawing the lab thermometer 
• Watch the given link for a better understanding of the concept - Lab Thermometer

That is all for today

See you soon.......