Chemistry Question - Different Chemical Properties of Basic Elements

Factual Questions
1

The properties of all basic elements are different. Different boiling points, freezing points, colors, etc.

Have we figured out what in the basic structure of the atom(protons, neutrons, electrons and whatnot) causes these differences and how?

For example, how exactly these extra proton, electron and neutron Lithium has over Helium make Lithium an Alkali metal instead of a Noble gas?

(20 minutes later)

I’ve done some thinking in the shower using my limited chemistry/physics knowledge…

It’s the electrons that change the charge of the atom. That’s obvius. Add electrons and get a negative charge, remove some and get a positive one.

If i’m not mistaken, different Isotopes of the same atom have identical chemical properties but have different reactions with other materials due to the extra neutrons, or something along these lines, I’m not sure about this one.

So that leaves us with either the Protons or something on a lower level we havent discovered yet that changes the chemical properties of basic elements.

But IANAChemist, I’d appreciate an answer from someone who knows what he’s talking about. :slight_smile:

2

Your question is very broad, and would take about a semester to properly address. :slight_smile:

The short answer to your question is yes, most of these things are understood quite well. There are numerous models used to explain your questions. Unfortunately, as these models’ precision increases, so does their complexity.

In any event, I’ll throw out a few things:

As atoms get larger, the so-called “London forces” between them increase. This explains why the melting points and boiling points of the noble gases, for example, increase as you proceed down the periodic table from helium to radon.

The basic chemical properties of elements are due to the number of electrons present in the neutral element. Since the number of electrons present in the neutral element must match the number of protons, we use the number of protons, also known as the “atomic number,” to define a given element.

Atomic size increases as you go down the periodic table, and decreases as you go from left to right on the periodic table. This affects an important property of elements called the ionization energy. The (first) ionization energy is a measure of how hard it is to remove the outermost electron from an atom. The smallest atom, helium, has the highest ionzation energy. The largest atom, francium, has the lowest ionization energy.

There are also preferred (lower energy) configurations of electrons. The noble gas configurations are the most stable.

For these reasons, the alkali metals tend to be very reactive in reactions that would cause them to lose an electron. The halogens tend to be very reactive in reactions that would cause them to gain, or share, an electron. The noble gases are not very reactive at all.

Color of elements is also affected by how light interacts with electrons, but I’m going to stop here.