Lithium

Lithium is the third element of the periodic table, and it’s reactive properties only get more destructive the further down you go in the periodic table. Even though hydrogen is directly above it, Lithium is in the general group of alkali metals, which is completely different than hydrogen’s group of nonmetals.

Lithium has an atomic mass of 6.941, atomic number of 3, and it has 2 stable isotopes, Li-6 and Li-7. Li-7 is the more common lithium isotope, that is the main type of lithium used in standard applications. Li-6 is a rare helium isotope, that is missing a neutron compared to Li-7. Li-7 makes up the majority at 94%. Both isotopes are indistinguishable from one another without specialized technology like mass spectrometers. Even though about two percent of the mass in the universe remains for elements other than hydrogen and helium to take up, lithium makes up a negligibly small 0.0000006% by mass. (From now on, all measurements will be by mass). In the atmosphere though, forget it. There’s zero percent. A tiny amount of lithium compounds will spurt up from the oceans once in a while, but the chance that you will breathe in one atom of lithium in your entire life even if you lived a millennia is basically zero. (Maybe I’m exaggerating, that’s for you to figure out. Hint: I actually am not).

Lithium is very electropositive, which is another way of saying that it really hates extra electrons and makes big booms when it reacts with things its way. Because of its electropositivity, it is almost never in covalent bonds, the sharing of electrons, because sharing would mean gaining electrons for both atoms, which might be good for one, but not for lithium. It’s not even a diatomic element, since that would require it to make a bond. All metals (like lithium) have some sort of structure in which they are arranged and a sea of electrons floats around them. That’s why metals are almost always solid and have a rather high melting point, because that crystal structure keeps them together. It’s chemical formula is simply “Li”, because you want to write the full chemical formula for a small piece, you’ll end up writing “Li_{10000000000000000000…}”. Lithium’s full electron shell is 1s²2s¹, and it’s noble gas configuration is [He] 2s¹. Lithium is the first element to even have a noble gas configuration. Lithium only makes metallic bonds (with other metals and with other lithiums) and ionic bonds to form lithium-based salts with halogens (Fluorine, chlorine, bromine, iodine, etc., sometimes hydrogen, as in Lithium Hydride).