What is the maximum number of electrons an orbital may contain?

The maximum number of electrons an orbital may contain is 2 electrons.

Explanation:

There are 4 atomic orbitals called s, p, d and f.

There are one orbital s and it has 2 electrons.

There are three orbitals p, each one contain 2 electrons and in total they have 6 electrons.

There are five orbitals d, each one contain 2 electrons and in total they have 10 electrons.

And there are seven orbitals f, each one contain 2 electrons and the maximum number of electrons this orbital can contain is 14 electrons.

5.0 cm

Explanation:

Recall that the formula for finding the magnification (M) of the image of a lens is given by:  , where is the distance from the lens at which we place the object (actually given as 12.0 cm), and is the distance from the lens at which the image appears (not given).

So clearly, we need to start by finding the distance at which the image appears. To do such , we use the lens formula:

we replace   with 12 cm, f with the given "-6 cm" (recall that diverging lenses carry negative focal distance), and proceed to solve for the unknown ( ). We will skip writing the units (cm) of both known distances, having present that the distance we find will therefore come in cm:

where the negative sign is telling us that the image appears on the "object side" of the lens.

Now that we know , we can estimate the magnification (M):

The magnification is positive (this means that the image is upright - not inverted) but smaller than one, which tells us that the image is smaller than (one third of) the object's size.

Then, if the object's size is 15 cm, the image's size will be one third (1/3) of it, that is: 5 cm and upright.

Then you need to select the last of the choices given: 5.0 cm