Chemistry is the scientific discipline involved with compounds composed of atoms, i.e. elements, and molecules, i.e. combinations of atoms: their composition, structure, properties, behavior and the changes they undergo during a reaction with other compounds. Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds.
squash requires a brief heat treatment, called blanching, in boiling water or steam, to destroy the enzymes before freezing. Cook (blanch) the squash for 3 minutes. Begin counting the blanching time as soon as you place the squash in the boiling water.
Freezing Broccoli: Blanching. After you have cut up the broccoli, you have to blanch it before you can freeze it. I can tell you from personal experience, frozen broccoli that was not blanched first, is not at all pleasant to eat - In fact it's AWFUL. Don't try to skip this step - you'll be disappointed.