1.Which properly shows that a liquid is pure?
2. A few drops of perfume were split on the floor. A few minutes later the perfume could be perceived a few meters away. Which two processes has taken place?
3.Which statement is an example of diffusion?
4. In which change of state do the particles become more widely separated?
5. A volume of gas 200cm^3 has a pressure of 510mmhg . Find its pressure when the volume was increased to 350cm^3 , provided that the temperature remains constant
6. The S.I unit for volume is
7. The atomic number of aluminium is
8. The origin of chemistry can be traced to the study of
9. Which of the following element is a metal?
10. The chemical symbol of mercury is
11. A gas of volume 260cm^3 at -40C. Find its temperature if the initial volume was reduced by half, provided that the pressure is constant.
12. Convert 70*C to kelvin
13. Boyles law is expressed as
15. The change of gas to solid is called
16. The combining power of an element is
17. Heavy rainfall lead to _______
18. The chemical formula of sodium hydroxide is
19. Elements are displaced in a chemical reaction due to _______
20. The collision between gas molecules are
