Blackheads differ from whiteheads because whiteheads are covered by skin, whereas blackheads are open to the air. What causes the dark coloration

Lipids within the sebum react with air, resulting in chemical oxidation and the formation of the black color.

Explanation:

This is the answer. I hope it helps you out.

Explanation:

When a charge is in an electric field, it experiences a force given by

where

q is the charge

E is the strength of the electric field

The field between two parallel plates is uniform, so it can be rewritten as

where

V is the potential difference between the plates

d is the separation between the plates

So the first equation becomes

In this problem we have:

is the magnitude of the charge

V = 250 V is the potential difference between the plates

d = 3.4 cm = 0.034 m is the separation between the plates

So the magnitude of the force is