The copper coin was in a evaporating dish containing zinc metal, tunred gray and then was heated in a busen burner.
Indeed, Copper mixed with Zinc produces the alloy Brass-'gold'. The Zinc stuck to the Copper, when you heated it you mixed the two. Your eyes mixed the two colors, not being able to see the little spots of copper and zinc separately, thus 'gold'. Get an A.
Are you talking approximately point magic? Very skillful manipulation of your perceptions. this is an phantasm. The coin became substituted by ability of the magician, in a pass which you have been distracted from seeing. If the magician reported my hand became in view the whole time and insists on that interpretation of activities, then there became in all hazard a 2d whilst the hand became no longer in view. i admire the close-up stuff, do no longer you? i think of understanding that your strategies is being messed with is an element of the relaxing.
Copper and zinc combine to make brass. For a while the fresh surface of the brass will look gold, over time it will oxide to reddish brown. The layer of zinc atoms on the surface of that penny are actually moving down into the copper when you flame it. A thin layer at the surface is becoming brass.
