Consider the following reactions. (Note: (s) = solid, (l) = liquid, and (g) = gas.)
Mg(s) + ½O2(g) → MgO(s) + 146 kcal/mole
H2(g) + ½O2(g) → H2O(g), ΔH = -57.82 kcal/mole
What type of reaction is represented by the previous two examples?
A: exothermic
B: endothermic

What are transitions between a liquid and gas called? identify which way they are transitioning

Two metal blocks that have slightly different temperatures are placed next to one another. after five minutes, they both have lower but equal temperatures. according to the law of conservation of energy, what  most likelyhappened? energy was created inside the blocks. energy was destroyed inside the blocks. energy was absorbed into the blocks from outside the system. energy was transferred from the warmer block to the cooler block.

Which statement correctly describes the phosphate ion, ? it is composed of one phosphorus atom and four oxygen atoms covalently bonded together, and there is a –3 charge distributed over the entire ion. it is composed of one phosphorus atom and four oxygen atoms covalently bonded together, and there is a –3 charge on the phosphorus atom. it is composed of one phosphorus atom and four oxygen atoms ionically bonded together, and there is a –3 charge distributed over the entire ion. it is composed of one phosphorus atom and four oxygen atoms ionically bonded together, and there is a –3 charge on the phosphorus atom.