Symbol used by Berzelius for oxygen is [O] and ______ for hydrogen. [H/O]

Explanation

To answer the question about the symbol used by Berzelius for hydrogen, we can follow these steps:

### Step 1: Understand the Question
The question asks for the symbol used by Berzelius for hydrogen, given that the symbol for oxygen is [O].

### Step 2: Recall Berzelius's Contribution
Berzelius was a scientist who proposed that elements should be represented by symbols, which are typically the first letter or the first two letters of their names.

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