Q. Helium gas is filled in ballons because (Solved)
1. its atomic number is 2
2. it is lighter than air
3. it is one of the constitutents of water
4. it is a noble gas
- b. it is lighter than air
1. its atomic number is 2
2. it is lighter than air
3. it is one of the constitutents of water
4. it is a noble gas