Bonding & Chemical Reactions
Some atoms are attracted to one another while others are repelled by one another. This behavior isn't too dissimilar from what we see with individual people, except atoms are a bit more extreme. When some atoms are attracted to each other, they are really attracted.
We aren't just talking about partners for life; we are talking partners for hundreds, thousands, sometimes, millions of years or more. Bond strength is an indicator of how great the attraction is between two atoms. There are several types of bonds in chemistry. For now though, let's just concern ourselves with the big picture. All types of bonds involve these little negatively charged particles called electrons.
Atoms that have too few electrons want more. Atoms with too many electrons want to get rid of some. Some atoms like to share. Others are pretty electron-greedy. Did we mention that atoms are kind of like people? If that's the case, electrons are chemical currency. When electron transactions take place, something really cool happens.
Chemical reactions are a result of bonding changes. During a chemical reaction, the atoms bonded together in the beginning rearrange in new ways. The result is different chemicals and at times, a release of energy. Check out this smorgasbord of cool chemical reactions.
There's one last thing to discuss. We would be remiss if we didn't introduce a chemical equation. Chemistry has its own language. Here is an example of a chemical equation that a chemist uses to describe a particular reaction:
Fe + S → FeS
To the left of the arrow, chemists list the reactants. These are the chemicals that we start with. When they are added together, a reaction occurs. Think: ka-boom. To the right of the arrow, chemists list the products. These are the chemicals that are made as a result of the chemical reaction.
The arrow serves as an indication of a chemical transformation. We mix together a little bit of iron (Fe), some sulfur (S), and voilà. We now have iron sulfide. Chemists represent this chemical compound as FeS.
Note: Subscripts are absent from this chemical compound. When subscripts are absent, we will always just assume one atom is needed to make the chemical compound. In the case of FeS, one atom of iron comes together with one atom of sulfur. Now, back to the equation.
Notice that the elements that are present on the left hand side of the chemical equation are the same as the elements present on the right hand side of the equation. Magic? No. Important? Yes. In chemical reactions, the elements never change. Instead, the bonding situation changes. As a result, there is a new chemical compound.