Question

I.aluminium oxide is called amphoteric oxide 2.an iron strip dip in a blue copper sulphate solution turns the blue solution to pale green.
3.hydrogen gas is not involved when most metals react with nitric acid 4.calcium does not occur in free state in nature 5 sodium or potassium metals are kept immersed under kerosene

Answer 1

Explanation:

5. If the total frequency is

19. The median of the following data is 52.5. If the

100, find the values of x and y.

Class 0-10 10-20 20-30 30-40 40-50 5

Frequency 2 5 X 12 17 2

on 20-30 30-40 40-50 50-60 60-70 70-80 80-90

12 17 20 1997