Those atoms have uneven numbers of electrons, unlike most atoms and molecules, which have electrons in pairs.

这些原子有不均匀数量的电子，不像大多数原子和分子，它们有成对的电子。

" 10 divided by 4" , now, sometimes you get an uneven number.

“10 除以 4” ，现在，有时你会得到一个奇数。