Does the reaction of hydrogen produce any products that negatively affect the environment?

The answer is NO. During combustion of hydrogen, water is produced as an end product. The chemical formulae for combustion of hydrogen are:

2H2 + O2 -->2 H2O

another advantage is that the whole of the fuel load is combusted hence little wastage. This has made the fuel advantageous in its use as rocket fuel since there is no baggage fuel.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.