Questions

A pure substance can be defined as any single type of material that has not been contaminated by another substance. In chemistry, a pure substance has a definite composition. It can be a compound or an element. A pure substance is considered to be a material that consists of one type of "building block" of matter.

Examples of pure substances include tin, sulfur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) and baking soda (sodium bicarbonate).

Tin, sulfur, and diamond are examples of pure substances which are chemical elements. All elements are pure substances.

Water, sugar, salt and baking soda are pure substances which are chemical compounds. Chemical compounds also are pure substances

All x86 processors have pipelined structure.

- Send the box with the lock to Alex. 

- Alex can't open it, but can put another lock on the box. 

- Alex sends this box with the 2 locks back to you, you unlock your lock and send it back to Alex again.

- So there is just Alex's lock on the box and Alex can now open it.

No circular or curved motion is possible without providing the necessary centripetal force. (C) provides this and so is the answer.