Questions

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.

FIFO (First In First Out) stack is used in 8086. In this type of Stack the First Stored Information is retrieved first.

a -  at the peak of changes in blood pressure indicates the systiolic pressure.

Answer A is tempting because the problem focuses on changes. However, because we are talking about the elaboration of the product's characteristics, we are talking about scope changes, and therefore Answer B is the best answer. Answer C is also tempting because it is difficult to more forward on a project until the scope is clearly defined (especially in systems development projects), but with products and certain types of web development, scope changes can be frequent, and a formal scope management plan is needed. Answer D is true from a project perspective, but does not addres the scope issues.