When aluminum oxidizes in air, it forms aluminum oxide (Al2 O3): 4 Al(s) + 302 (g) → 2 Al2 O3 (s)
A 51 g sheet of aluminum oxide formed completely in excess oxygen.
How many grams of aluminum were oxidized?

27 g
0 51g g
54 g
102 g

The internal energy of the system we can term it as total potential energy and kinetic energy. energy flows out of the surrounding from the system then we can say that the internal energy of the final state is lower than its initials. the sign of  δesystem is negative.δesystem = efinal - einitial=-ve  efinal  ∠einitial.

Chromosomes can be used more than once atoms are all different