Now, letâs get down to business â the cost! They do offer a 30 day free trial and then after that it is $7.95 a month or $79 a year. After just a few weeks of Nathan playing, I personally feel that the $7.95 a month is totally worth it!
A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position.
Molecular Weight and the Mole The weight of a molecule is the sum of the weights of the atoms of which it is made. The unit of weight is the dalton, one-twelfth the weight of an atom of 12 C. Thus the molecular weight (MW) of water is 18 daltons. (We shall ignore the tiny error introduced by the presence of traces of other isotopes - 17 O, 18 O, and 2 H among the predominant 1 H and 16 O atoms.) Why is it important to know the molecular weight of a compound?