Mar 8-12

This week, I learned about molecular compounds through the practice problems I did in class.

A molecular compound is formed when two or more nonmetal elements combine to form a compound. They attract through sharing, not transferring electrons. This then differentiates between ionic and nonionic compounds.

Ionic bonding=transferring and receiving of electrons

The differences between an ionic and a molecular compound are that an ionic is form by metal and nonmetal elements that attract to each other because of their opposite charges (+ metal and - nonmetal) and transferring of electrons to neutralize their charges. On the other hand, a molecular compound is form when the nonmetal elements play tug of war with electrons but don't transfer them. Hence, molecular compounds don't have neutral charges. They are negatively charged for the most part.

Because molecular compounds don't share electrons, I realized that they bonded in different ways. They share electrons through covalent bonding, which occurs when the negatives in atoms don't attract due to the negative nonmetal elements. Instead, they repel and reveal the positives. This then creates an overlapping area of electrons. The electrons are shared between the two atoms combined. The mobile electrons in the molecular compound rotate anywhere, but mainly near the more slightly positive atom due to a weak attraction between the electrons and the atom. But, the electrons, when they approach the other electrons, repel, due to the same negative charges.

This week, I also learned about how to combine molecular compounds and ionic compounds as well. To combine ionic compounds, the ions must neutralize in order to form an ionic compound. One of the board problems I did involved combining a "polyatomic ion" (a negatively charged conglomeration of many atoms) with a transition metal. To solve those, I knew I had to know the charge of the polyatomic ion first since the transition metal's charge varies depending on the charge of the other element. This is because an ionic bond attracts the transition metal and the nonmetal polyatomic ion together, forming a neutrally charged ionic compound.

Copper I Nitrate

For example, in Cu(NO4), the charge of copper would be +1 since the nitrate has a charge of -1. As the copper combines with the nitrate, the nitrate transfers electrons to copper, neutralizing copper and nitrate. With the needed electron in NO4, not only does the charge become neutral, but I also think that an ionic bond now holds N and O4 together, making their attraction to each other even stronger. Therefore, the new ionic compound formed is Copper (I) Nitrate. The Roman numeral indicates a transition metal's charge.

I also wondered about labeling chemical compounds if the subscript of each was a certain number. If I had to label the specific compound, what would I call it? For example, what would I call N5O2? Knowing that there are 5 nitrogen atoms and 2 oxygen atoms, this compound is called penta-nitrogen dioxide. Therefore, I learned that depending on the subscript of the elements, you use the prefix (tetra, for example, to represent four) and put it before the element. The second or last element in the compound has the suffix -ide at the end, except with hydrogen.

Covalent bonding=sharing of electrons

One of the baffling things also seemed to center around the polarity between H2O. I am not sure as to why, but oxygen has an uneven pull on the hydrogen atoms. But, how can this be when they have a neutral charge? It seems to me that polar substances only form if the compound isn't neutrally charged. Therefore, I think it's possible for molecular compounds to have polarity.

In H2O, the electrons seem to attract to one other H atom, making it more negative, and the other one more positive. Knowing that the electrons repel each other and are mobile, they can move around the more positive H atom. But, for the most part, the electrons surround the other H atom. Because of this, I wonder if this may be linked to or causes its polarity.

I also wonder if two nonmetal elements combine and have a neural charge, then would they form an ionic compound or a molecular compound. An example I can think of this is C(NO3)4 because carbon has +4 charge and (NO3)4 with a charge of -4, hence forming a neutral charge. This I seemed to struggled with because I like to think that there is always a grey area in between and that things aren't just black and white. I think C(NO4)4 is an ionic compound because carbon has a charge of +4 and NO4 has a charge of -1, so C(NO4)4, logically, would neutralize and become ionic through ionic bonding. But, then C(NO4)4 could be a molecular compound because carbon and nitrate are both nonmetals and carbon may transfer or receive electrons depending on other atoms it combines with. Finding more support for the latter choice, I think it's most likely a molecular compound since both are nonmetals.