molecule. 1  Chemistry, Physics. the smallest physical unit of an element or compound, consisting of one or more like atoms in an element and two or more different atoms in a compound. 2  Chemistry. a quantity of a substance, the weight of which, measured in any chosen unit, is numerically equal to the molecular weight; gram molecule.
When I do crunches my neck starts to tighten up and it makes me have to rest before doing another set of crunches.
1. Face firming gymnastics are very effective and will tone, raise, and firm up turkey neck (tighten saggy neck skin) - which is the same thing as a no surgery neck lift. 2. Double chin exercises will help with lessening and tightening the tissue and loose skin along the jawline. This will give you a leaner face. 3.. Face firming gymnastics are very effective and will tone, raise, and firm up turkey neck (tighten saggy neck skin) - which is the same thing as a no surgery neck lift. 2. Double chin exercises will help with lessening and tightening the tissue and loose skin along the jawline. This will give you a leaner face. 3.