Most of the ultraviolet radiation reaching the surface of the earth is UV-A radiation, which has a wavelength range of 315 nm to 400 nm. UV-A radiation is a cause of skin aging and also contributes to development of skin cancer. Determine the energy of a mole of photons of UV-A radiation that have a wavelength of 325 nm.

6.1 ×10^-19 J

Explanation:

From E= hc/λ

h= planks constant = 6.6×10^-34 Js

c= speed of light = 3×10^8 ms^1

λ= wavelength = 325 nm

E= 6.6 × 10^-34 × 3×10^8/325 × 10^-9

E= 0.061 × 10^ -17 J

E= 6.1 ×10^-19 J

pure water does not conduct electricity very well. however, when certain substances are dissolved in water, the solution does conduct electricity. you can make a simple device that shows how well a solution conducts electricity. this device uses a flashlight bulb to indicate how well the solution conducts electricity. the better the solution conducts electricity, the brighter the bulb will glow.

explanation:

organisms are more likely to be more preserved in mud than sand because mud is moist and wet, while sand is very dry.