1. Is brass a heterogeneous or a homogeneous mixture?
2. Why did brass form only after placing the zinc-coated penny in a flame?
2007-03-08 08:06:23 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Brass is a homogeneous mixture of Copper and Zinc. As for question two, you have to know that pennies now days are not solid copper. They are a zinc core coated with a thin layer of copper. By heating the penny, you cause some of the zinc and copper to become an alloy giving you the yellowish color.
Interesting fact... Old pennies, ie the ones made of solid copper before they changed to a zinc core, are worth more than 1 cent each. That's one reason why the US mint changed to a zinc core. There was actually a decent run on taking copper pennies to the recycling center and making some $ on the value difference of the metal vs the face value.
2007-03-08 08:20:04 · answer #1 · answered by CurazyJ 2 · 0⤊ 0⤋
1. homo
2. cuz the flame melted the zinc coating and the copper just under it and they mixed to form brass.
2007-03-08 16:10:29 · answer #2 · answered by Anonymous · 0⤊ 0⤋