Questions

There are two kingdoms of bacteria. They are

1. Eubacteria  and 

2. Archaea

The members of these two kingdoms appear similar in shape and appearance, even under the extreme magnification of the electron microscope . However, they are very different from each other in a number of molecular and biochemical aspects. It is these differences that have resulted in the microorganisms being grouped into separate kingdoms.

For example, eubacteria contain the rigid, stress-bearing network known as the peptidoglycan . The only exceptions are the bacteria from the genera Mycoplasma and Chlamydia. Archaebacteria do not contain peptidoglycan. Instead, they contain a different structure that is called pseudomurein.

The common bacteria belongs to Eubacteria kingdom.

We know that, Elements in the same group of the periodic table have similar characteristics.

Here Magnesium and Strontium shared some similar properties because they both belong to the same group. Sr is the chemical symbol for strontium which is a group two element; it has atomic number of 38. 

CF4 is tetrahedral.

Since the four 'F' atoms have the same electronegativity values, there is no bias in electron distribution toward any one.

Therefore, electron/charge distribution is symmetrical, which also means that the molecule is nonpolar.

Hence, CF4 is nonpolar molecule with a symmetrical distribution of charge.