The oxidation number of hyrogen is
(i) `0`
(ii) ` +1`
(iii) ` -1`
(iv) `+ 1` only.

Explanation

To determine the oxidation number of hydrogen, we can analyze its behavior in different compounds. Here’s a step-by-step solution:

### Step 1: Understand the basic properties of hydrogen
Hydrogen has an atomic number of 1, which means it has one electron. This electron is in the first shell and in the s subshell.

**Hint:** Remember that the oxidation state can change based on the type of bond formed with other elements.

### Step 2: Determine the common oxidation states of hydrogen
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