For number one the answer is Iodine because it is in the same group as fluorine. For number two the answer is Germanium for the same reason. For number three the answer is Aluminum for the same reason.
The answer is radio waves
You may confuse two minerals by their colors so using streak is another way for showing their "true colors "
Answer: C
Explanation: Side post terminals need to be removed to inspect them for corrosion.
Over tightening the terminal bolt can damage side post terminals.
The battery terminals and cable ends can corrode especially when the battery or car is not used for a long period of time. Corrosion limits a battery's lifespan and so should be prevented. To inspect the areas where corrosion occur on a side-post battery, you need to remove the terminals.
Also, it is true that over tightening the terminal bolt can damage the side post terminals. The covering on the battery can become twisted, and make the seals on the terminals leak.