substance a decomposes at a rate proportional to the amount of a present. it is found that 12 lb of a will reduce to 6 lb in 4.2 hr. after how many hours will there be only 1 lb left?

Your answer is: increased air temperatures  hope this ! : )

Hiya! this would be resolution  good-luck!

Each eukaryotic cell has a plasma membrane, cytoplasm, a nucleus, ribosomes, mitochondria, peroxisomes, and in some, vacuoles; however, there are some striking differences between animal and plant cells.