Question

1. Define an element.
2. Give two examples each of the following:
(a) elements (b) compounds
3. How are compounds classified ?
4. Which of the following is correct: 293 K or 293"K?
5. Show that the SI unit of force has the dimensions kg m
6. Which zero in a number is significant ?
7. Name all the laws of chemical combination,
8. State the law of conservation of mass.
9. State Avogadro's hypothesis.
10. Define molar volume of a substance.
11. Show that, Molecular mass - 2 x Vapour density.
12. Define atomic mass Unit.
13. In what respect do the atomic mass and relative atomic
mass of a substance differ?
14. Define the term mole.
15. How many particles are there in one mole of a substance?​

Answer 1

• it is a substance that is made entirely from one type of atom .
• H2 ,O2 and H2O ,CO2.
• 293K
• mass is neither be created nor be destroyed in a chemical reaction .
• 6.022×10^23
• the mass of substance containing the same number of fundamental units, depending on the substance.