How many electrons are there in the outermost shells of fluorine (f) atoms?

a. 2
b. 7
c. 9
d. 19

C. 9

There are 2 electrons in the first shell, and 7 in the second, for a total of 9.

A flouride ion, on other hand, would have 8, since it fills that second shell with an extra electron (that's why it has a charge of -1)

why is arctic sea ice important? arctic sea ice keeps the polar regions cool and moderate global climate. sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space. as sea ice melts in the summer, it exposes the dark ocean surface.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.