60 kg of aluminum at 15C° is placed into 20 kg of 90C° water. If no heat is exchanged with the surroundings, find the final temperature of the two.

A. to determine if humans can explore mars safely

In atoms, the electron carries a negative elementary or unit charge; the proton carries a positive charge. the two types of charge are equal and opposite. in an atom of matter, an electrical charge occurs whenever the number of protons in the nucleus differs from the number of electrons surrounding that nucleus.