Questions

The approval by the Architecture Review Board is a milestone you want to include in activity sequencing so that you can ensure the requirements for meeting the review board's approval are met.  Answer A is tempting because the question references phase-end activities; however, it is not an example of gatekeeping because the project is not being authorized to continue based only on the architecture review.Gatekeeping often involves the review of other factors as well. Answer C is incorect because the requirement of a review board approval does not afect scope. Answer D is incorrect because project integration planning involves project plan development, execution, and integrated change control, which are not related to a review board.

Diamond is the hardest substance available on Earth.

Diamond is the hardest substance available on Earth due to the giant molecular structure of diamond in which each carbon atom is covalently bonded to four other carbon atoms. A covalent bond is very strong and requires a large amount of energy to break itself, and diamond has many covalent bonds.

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

George Orwell in 1984