What word does this rebus represent?

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Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

What's a single-digit number with no value?

Pronounced as 1 letter, And written with 3, 2 letters there are, and 2 only in me. I’m double, I’m single, I’m black blue and grey, I’m read from both ends, and the same either way. What am I?

What does below chemistry rebus means?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

I know a nine-letter word having only one vowel.
Do you ?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?