Answer:
Magnetivity and melting point.
Explanation:
Aluminum, steel and tin cans can be separated by two step process of magnetisation and melting point, because the three cans have different magnetic properties.
Steel attract to magnet easily because of it's has magnetic properties and these separate steel from aluminum.
Neither steel and aluminum melted at 300°C but Tin melt at that temperature.
Catalyst can speed up chemical reaction without being used up or involved in thr reaction..
No one is 100% sure when particles of matter originated however scientist believe it had to be some time before the Big Bang
