Iron rusts when exposed to air → chemical property
Answer: The answer is C. The reaction system absorbs 22 kJ of energy from the surroundings.
Explanation: I just took the quiz and it said I got it right.
Period are going left to right across the periodic table
Groups are going up to down on the periodic table
Be a chemist. Lol. Lessen waste, make chemicals more efficient, cure diseases... and stuff :)