Can two or more elements be combined chemically to make a new element? explain your answer.

I think it's quite simple.

An element is basically a group of similar atoms combined. For example, gold atoms combine to form a gold element (metal).
A compound is the product of the chemical combination of two or more atoms. For example, two Hydrogen atoms and an Oxygen atom combine to form water (a compound).
And a mixture is the product of the physical combination of two or more substances (not chemically combined). For example mixing water and milk powder. I hope it was helpful.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).