Explanation:

Let’s break it down:

- Mercury boils at 357°C—that’s the exact temperature we’re looking at here. Heat it to that point, and it turns from liquid to gas. Mercury is basically the poster child for this scenario.

- Copper? Not even close. Its boiling point is around 2562°C. You’d need a much hotter oven.

- Bronze isn’t even an element. It’s a mix (alloy) of copper and tin, and its boiling point is all over the map depending on what’s in it.

- Gallium is a soft, silvery metal, but its boiling point is way higher, at around 2204°C. So you’re not getting gallium vapor at 357°C.

So, the correct answer is Mercury.