Answer:
The answer to your question is: letter D.
Explanation:
a.The mass that a mole of substance has, measured in grams per mole. Density is not measure in moles, so this is not the correct answer.
b.The amount of substance dissolved in a liquid, measured in moles per liter. The substance dissolved in a liquid must be measure in grams not in moles, so this answer is incorrect.
c.The mass of substance dissolved in a liquid, measured in grams per milliliter. I think that this definition is correct but is incomple, so this answer is wrong.
d.The ratio of a substance's mass to its volume, measured in grams per milliliter and also equivalent to grams per cubic centimeter. This is the right description to density, so this is the correct answer.
<span>c. atoms are always in motion..............</span>
Answer:

Explanation:
Asúmase que la patinadora experimenta una aceleración constante. La fuerza neta experimentada por la patinadora:
![F_{net} = (50\,kg)\cdot \left[\frac{\left(15\,\frac{m}{s}\right)^{2}-\left(0\,\frac{m}{s}\right)^{2} }{2\cdot (3000\,m)} \right]](https://tex.z-dn.net/?f=F_%7Bnet%7D%20%3D%20%2850%5C%2Ckg%29%5Ccdot%20%5Cleft%5B%5Cfrac%7B%5Cleft%2815%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%5Cright%29%5E%7B2%7D-%5Cleft%280%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%5Cright%29%5E%7B2%7D%20%7D%7B2%5Ccdot%20%283000%5C%2Cm%29%7D%20%5Cright%5D)
