Answer: a) 8.2 * 10^-8 N or 82 nN and b) is repulsive
Explanation: To solve this problem we have to use the Coulomb force for two point charged, it is given by:

Replacing the dat we obtain F=82 nN.
The force is repulsive because the points charged have the same sign.
Answer:
A. polymerization
Explanation:
Synthetic plastics are made by linking many simple carbon molecules together to form much larger molecules. This process is called polymerization.
Synthetic or artifical giant molecules consists of synthetic polymers such as plastics, elastomers etc. They are made up of simple monomers which links to form the complex and giant structure.
Monomers are the simplest unit of polymers. Polymers have very great sizes. The size mkaes their structure quite complex. This makes the molecules more disposed in a regular pattern with respect to one another.
The complexity of structure and the attendant effects accounts for the properties and uses that makes synthetic molecules very unique. For example, plastics can be extruded as sheets, pipes and or moulded into other objects.
Angular acceleration = (change in angular speed) / (time for the change)
change in angular speed = (zero - 2,600 RPM) = -2,600 RPM
time for the change = 10 sec
Angular acceleration = -2600 RPM / 10 sec = -260 rev / min-sec
(-260 rev/min-sec) x (1 min / 60 sec) = <em>-(4 1/3) rev / sec²</em>
Since the acceleration is negative, the motor is slowing down.
You might call that a 'deceleration' of (4 1/3) rev/sec² .
The average speed is 1/2(2,600 + 0) = 1,300 rev/min = (21 2/3) rev/sec.
Number of revs = (average speed) x (time) = (21 2/3) x (10sec) = <em>(216 2/3) revs</em>