The word temperature is a frequently spoken word, while discussing how the weather is today such as warm, hot or cold. The weather news always have temperatures of different places. Doctors often checks the temperature of body of a patient. Temperatures are often used to tell the extreme weathers on earth like the coldest places in Siberia and the hottest countries in sahara deserts. Many fields of science like physics, chemistry environmental science and material science are much dependent on use of temperatures. The home appliances we use like induction cooktops, smart refrigerators, electric kettles, ovens etc. all works with certain temperatures.
Measurement of temperature
Temperature can be measured also same like length, mass and time. Hotter objects have more value of temperature than the colder objects.
Sun light on earth is felt warmer than a snowy day in winters.
Human body feels hotter in fever than without fever.
By definition, temperature refers to the degree of
hotness or coldness of any object. The hotness and coldness of objects are measured in numeric values
alongside by writing the units of
temperature.
There are three units of temperature which are used to measure it.
- Celsius or centigrade
- Fahrenheit
- Kelvin
Celsius or centigrade
Celsius is named after the Swedish astronomer Anders Celsius who proposed its first version in 1742. The degree Celsius is the unit of temperature. The symbol for degree Celsius is °C. Celsius was called as centigrade initially before 1948. To honour the swedish scientist Anders Celsius, it was renamed from centigrade to Celsius in 1948.
The unit of temperature was named as centigrade because there is a difference of 100 between temperature of freezing and boiling point of water. THe freezing point of water is 0 °C and boiling point of water is 1000 °C. The difference between them = 100 -0 = 100. The “centi” in centigrade refers to 100.
The interesting part in naming of the unit celsius is that Anders Celsius created a scale of 100 but considering the 0°C as boiling point of water and 100°C as the freezing point of water. But this scale was inverted after his death and the today’s temperature scale has 0°C as freezing point of water and 100°C as boiling point of water.
- 0°C is called freezing point of water. It is read as 0 degree celsius.
- 100°C is called boiling point of water. It is read as 100 degree celsius.
Celsius scale
The celsius scale is a scale which is marked with values starting from 0 to 100. 0 on celsius scale represents freezing point of water and 100 represents the boiling point of water. On celsius scale the temperature of any object can be noted down by looking at the level of the liquid reached against a marking on the scale.
Fahrenheit
Fahrenheit is also a unit used to measure temperature. It is widely used in the United States. The unit Fahrenheit has been named after the name of physicist Daniel Gabriel Fahrenheit who invented it. The unit of fahrenheit is written as °F and read as degree fahrenheit.
- 32°F is the freezing point of water in fahrenheit.
- 212°F is called boiling point of water in fahrenheit.
Fahrenheit scale
Fahrenheit scale was introduced by Daniel Gabriel Fahrenheit in 1724. This scale has the marking of lowest temperature of 32°F and the highest marking of 212°F. The difference between the two temperatures is 212 – 32 = 180°F.
Kelvin
The unit of temperature Kelvin was developed by The British scientist William Thomson also known by name Lord Kelvin in 1848. Kelvin unit was accepted as SI units also. SI is the International System of Units which defines the system of measurements that are most widely used in the world. The unit of kelvin is written as K and read as kelvin.
- 273.15 K is the freezing point of water in kelvin.
- 273.16 K is temperature where all three states of water solid, liquid and gas co-exist.
- 373.15 K is the boiling point of water in kelvin.
Kelvin scale
Kelvin scale was introduced by William Thomson as an absolute scale. Absolute scales are the positive scales that measures only in positive numbers not in negative numbers. This scale starts with the temperature reading of 0 K, where 0 K is the lowest theoretically possible temperature where all particles motion of a matter stops. 0 K on Kelvin scale shows the temperature of water where three water crystallizes into its solid form of ice. The lowest temperature that can be noted down on kelvin scale is 0 K and the highest marking of 273.15 K.
Conversion of celsius into fahrenheit
The temperature noted on celsius scale can be converted into fahrenheit and vice versa.
If the value of temperature in celsius is given, then it can be converted into fahrenheit using the
following
steps:
- Step 1: Multiply the value of temperature in °C with 1.8
- Step 2: Add the number 32 to the value obtained in step 1.
Th following formula can also be used directly to get fahrenheit from celsius.
or
Convert 40°C into fahrenheit.
= 9 × 8 + 32
= 72 + 32
= 104°F
Conversion of fahrenheit into celsius
The following formula is used to get change fahrenheit into celsius.
Convert 98.6°F into celsius.
= 37°C
Conversion of kelvin into celsius
The temperature in kelvin can be changed into celsius by simply subtracting it from 273.15
°C = K – 273.15
Convert 473.15 °F into celsius.
°C = K – 273.15
= 473.15 – 273.15
= 200 °C
Conversion of celsius into kelvin
Celsius can be changed into kelvin by adding 273.15 value to the temperature in kelvin.
°K = C + 273.15
Convert 100 °C into kelvin.
°K = C + 273.15
°K = 100 + 273.15
= 373.15 °K
Fill in Blanks Worksheet
| Type: | Blanks |
| Count: | 1 |
- The normal human body temperature is ___________ °F.
- The boiling point of water is ___________ °C.
- The freezing point of water in Kelvin is ___________ K.
- The range of temperatures on the Fahrenheit scale goes from 32 °F to ___________ °F.
- 100 divisions on celsius scale are equal to ___________ divisions on fahrenheit scale.
- The value of temperature on fahrenheit scale is the same as that on the celsius scale at ___________ °.
- 20 °C = ___________ °F.
- 230 °F = ___________ °C
- 98.6 °F = ___________ °C.
- 37 °C = ___________ K.
Match Columns Worksheet
| Type: | Matching |
| Count: | 1 |
| 1) | 10 °C | a) | 86 °F |
| 2) | 40 °C | b) | 104 °F |
| 3) | 100 °C | c) | 68 °F |
| 4) | 20 °C | d) | 122 °F |
| 5) | 30 °C | e) | 212 °F |
| 6) | 50 °C | e) | 50 °F |
Solve Questions Worksheets
| Type: | Solve Questions |
| Count: | 2 |
Convert celsius into fahrenheit.
- 25 °C
- 0 °C
- 60 °C
- 90 °C
- 45 °C
Convert fahrenheit into celsius.
- 212 °F
- 131 °F
- 95 °F
- 41 °F
- 104 °F
