why do some microwave popcorn leave unpopped kernels?

Question

Thius is my science work and for my certificate
please give good answers

Answer 1

It's long been known that popcorn kernels must have a precise moisture level in their starchy center -- about 15 percent -- to explode. But Purdue University researchers found the key to a kernel's explosive success lies in the composition of its hull.

Unpopped kernels, it turns out, have leaky hulls that prevent the moisture pressure buildup needed for them to pop and lack the optimal hull structure that allows most kernels to explode.

Seeing as how the cheaper brands yielded more unpopped kernels, it sounds as though it may have something to do with the quality of the corn used.

Answer 2

because the heat does not reach all the kernels and thus they don't pop.

Answer 3

They are not of good quality. So do not pop up.