The energy necessary to start any
chemical reaction
the insoluble solid formed when the
solutes dissolved in two solutions react
reactions in which the products
contain more energy than the reactants
reactions in which the products
contain less energy than the reactants

weather forecasts are done by collecting data about the current state of the atmosphere mainly the temperature, humidity and wind and using meteorology, to determine the atmosphere that evolves over time. the h and l mean the high and low pressure. the red strip is a warm front. the blue strip is a cold front. the blue and red strip is a stationary front. the purple strip is a occluded front.

explanation:

i think the answer is a, hope this : )

root word, prefixes, and suffixes