Study of the First Element - Hydrogen

goals
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?