An angle of incidence of 20.0° in water results in an angle of refraction of 15°. a)Is the second medium more or less optically dense than the first medium?
b)Find the n of the second medium
c)Repeat this question for an angle of refraction of 25.0°

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )

28. evolution

29. environment, survive, offspring  

explanation:

the temperature and the pressure affect solubility. temperature affects by changing the properties of the solvent. the increase in pressure increases solubility, the decrease in pressure decreases solubility.

the five characteristics of adolescence are biological growth and development, and undefined status, increased decision making, increased pressure and the search of self.