True or false atoms of difference elements can combine to form compound?

It's true

There are thousands of combinations that can be put together to form a all sorts of compounds. That's the whole basis of inorganic chemistry. Organic chemistry is a little bit different. It is more restricted.

passing a magnet thought the

mixture , because iron gets attracted to magnet .

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."