Study of the First Element - Hydrogen

The $$\displaystyle \frac{n}{p}$$ ratio of $$_1H^1$$ is :
The colour of hydrogen is :
When steam is passed through zinc, then:
Which of the following cannot be oxidized by $$H_2O_2$$?
A sample of water was  found to contain dissolved oxygen to the extent of 4ppm and hardness due to $${ Ca }^{ 2+ }$$ ions as 3ppm, then amount of  $${ O }_{ 2 }$$ and no. of  $${ Ca }^{ 2+ }$$ ions 1 Lt of water is?