A student is measuring the effect that surface area has on the rate of chemical weathering. He dissolves several 5-gram
samples of calcite in an acid. The samples range from a single rock, to several small pieces, to a fine powder. He observes
that the 5 grams of powder dissolve the fastest, and the single 5-gram rock dissolves the slowest. Based on this
information, how might mechanical weathering affect the rate of chemical weathering?

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.

answerclassical conditioning;