Same word, new meaning
Science gives everyday words one exact meaning.
A word in the lab
Meera says, “My reaction to the news was a big smile.” Her chemistry teacher says, “Watch the reaction in the test tube.”
What does “reaction” mean in the test tube?
What this lesson covers
The idea
Everyday words such as force, work, cell or reaction have specific meanings in science, which uses a shared language of terms, symbols and units; each quantity has a symbol and a defined unit.
A word in the lab
Meera says, “My reaction to the news was a big smile.” Her chemistry teacher says, “Watch the reaction in the test tube.”
What does “reaction” mean in the test tube?
- A smile or a feeling
- Substances changing into new substances
- Someone shouting
Words and symbols
First, give each everyday word its science meaning.
Now match each quantity with its symbol and unit.
One shared language
Everyday words such as force, work, cell and reaction have specific meanings in science. Science uses a shared language of terms, symbols and units. Each quantity has a symbol and a defined unit.
Because the words, symbols and units mean the same everywhere, a scientist in Kerala and one in Japan read “F = 10 N” in exactly the same way.
- Quantity | Symbol | Unit
- mass | m | kilogram (kg)
- velocity | v | metre per second (m/s)
- force | F | newton (N)
- electric current | I | ampere (A)
Notes
Everyday words like force, work, cell and reaction have specific meanings in science. Science uses a shared language of terms, symbols and units. Each quantity has a symbol and a defined unit.
Check yourself
“The police force arrived.” In science, what does force mean?
Which pair is the correct symbol and unit for mass?
A student writes “I = 3 N”. What is wrong?
Why does science use a shared language of terms, symbols and units?
- A group of police officers. That is the everyday meaning. Science has its own.
- A push or a pull on an object — correct. Yes. That is the meaning in science.
- A very strong feeling. Not in science. A force is a push or a pull.
- F, newton. That is for force.
- v, m/s. That is for velocity.
- m, kilogram — correct. Yes. Mass is m, measured in kilograms.
- I is electric current, and its unit is the ampere (A), not the newton — correct. Yes. The newton (N) is the unit of force.
- Nothing is wrong. Check the unit. N is for force, and I is current.
- Symbols should never be capital letters. Many are capitals, like F and I.
- So scientists everywhere can describe, compare and build on results clearly — correct. Yes. Everyone reads the same thing.
- To make science sound difficult. The aim is the opposite: to be clear.
- So that everyone has more words to memorise. The aim is clear communication, not memorising.