[Mariana (OP)]

Maya wants to know:

Where can I buy mercury? I would like some for a science experiment but have no clue where it’s sold.

What do you think?

[Kryptid]

You can find it on Amazon: https://www.amazon.com/Mercury-Metal-99-Pure-50g/dp/B01NAGXPOB/ref=sr_1_2?keywords=mercury&qid=1550077444&s=gateway&sr=8-2

Please do be careful with it, as it's poisonous.

[evan_au]

Keep it sealed, as the vapor is toxic
..and dispose of it carefully, as it is toxic in liquid form
...and many of the solid compounds are also toxic.

Definitely don't tip it down the sink, as it will sit in the "S" bend.
- and don't put it into landfill

You would need to find a chemical collection/disposals/recycling organisation.