Yes; this process if called nuclear fusion, and an example of it is in the sun. Elements in the sun are combined to create heavier elements in order to provide fuel.
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.
