Question

The element of the third period of the periodic table are given below.

Group I II III IV V VI VII

Period 3 Na Mg Al Si P S Cl

a) Which atom is bigger among Na and Mg? Why?

b) Identify the most (i) metallic and (ii) non-metallic element in period 3.

2. Do you observe yellow light in street lamps? What will produce yellow light?

3. What is "Dioptre"?​

Answer 1

Answer:

a) Na is bigger

b) i)Na ii) cl

2)yes,chlorine

3)The SI unit of power of glass or lens is Dioptre