<span>food chains follow just one path of energy as animals find food.
</span>food webs show how plants and animals are involved in ways to help them all survive.
Answer:
Reaction 1
Explanation:
Reaction 1 would be the most suitable in this case. This is so because in reference to the question you are wanting to keep the food warm over long periods. So in reference to the data in the chart reaction 1 continues to heat up over long periods of time. However, with the other reactions (2, 3, 4) temperatures vary and some even decrease constantly. Therefore showing that the other reactions are invalid to help reach your goal referencing back to the question.
B. Because of the presence of hydrogen sulphide in Brass, it combines with oxygen in air and form water, evaporates. So remained sulphide is colourless in air .So Brass gets discoloured in the air.