1. The property of elements showing similar properties at a regular interval is called ……………………………….
2. Periodic table shows elements in order of their ……………………… number.
3. How much percentage of elements in a Periodic table are non-metals?
(a) More than 80%
(b) Less than 20%
(c) 50%
(d) 60%
4. Element that form + ion like group 1 but behaves mostly like non-metal, is………………………..
5. From Neptunium to Lawrencium, elements are ………………………..and decay quickly.
6. When you go across a period from left to right, it changes from …………..………… to ………………………….
7. The elements of group 1 that are violently reactive and not suggested to keep in school lab are:
…………………………………………….
……………………………………………
…………………………………………..
8. Group 1 metals are known as ………………………….. metals.
9. Guess the blanks with the concepts you learned about the physical properties of Group 1 metals:
| Metal | This metal is silvery and | Density in g/cm3 | Melts at /oC |
| Lithium, Li | Soft | 0.53 | 181 |
| Sodium, Na | A little softer | 0.97 | 98 |
| Potassium, K | Still softer | 0.86 | …A…… |
| Rubidium, Rb | Even softer | ……B….. | 39 |
| Caesium, Cs | The softest | ……C…… | …D….. |
10. Li, Na and K reacts with water to give metal ………………….. and ……………………gas.
11. The alkaline solution changes its color to …………………….when a few drops of methyl orange is added to it.
12. Halogens are :
(a) Metals
(b) Non-metals
(c) Metalloids
(d) None of these
13. Which one of the groups have mono atomic elements:
(a) Group I
(b) Group VII
(c) Group VIII
(d) None of these
14. Density and Boiling point of group VII elements ………………………..as we go down the group.
(a) Remains same
(b) Decreases
(c) Increases
15. Fill the following table with the colour of elements at room temperature:
| Elements | Colour at room temp |
| Bromine | |
| Iodine |
16. Complete the appearance table of product after the reaction of halogens with Iron wool:
| Halogens | Appearance |
| Bromine | |
| Iodine |
17. Halogens form ………………….bonds when they react with metals.
18. Halogens form…………………..when they react with non-metals.
19. Write the chemical reaction for the following:
(a) When chlorine water is added to a colorless solution of potassium bromide, the solution turns orange.
……………………………………………………………………………………………………………………………………
(b) When chlorine water is added to a colourless solution of potassium iodide, the solution turns red-brown.
……………………………………………………………………………………………………………………………………..
20. Write the balanced chemical reaction for the following word reaction:
(a) Sodium metal reacts with chlorine to form sodium chloride
……………………………………………………………………………….
(b) Iron wool reacts with fluorine to form iron fluoride
…………………………………………………………………………………………
21. Reactivity of elements increases as we go down the group. This is true for which group?
(a) Group I
(b) Group VII
(c) Group VIII
(d) None of these
.