This tea.........tastes like.........AS!!!!!*dies*

Atomic Structure!

Augh! Sheesh.  Is that a drawing?  Yes, yes it is.  And I drew it because Mr. Ludwig wants us to cite picture sources and I just don't want to do that yet.  Besides, my tea cups are so cool.  It's almost better than most of my submissions to DeviantArt.  But I digress.
AS is the abbreviation for arsenic on the Periodic Table of elements.  Arsenic's Periodic data is also the reason I have the Periodic Table taped to my wall.  If you'd care to count the lovingly sketched electrons flying around the nucleus you'll count 33, which makes it arsenic because one must assume that 33 electrons means 33 protons.  How do I know?  Magic, but I'll explain it to you.  Eventually.

The picture lives here.

The atomic number, in the top left corner of this picture, is the number that represents how many protons are in the atom.  The protons are the positively charged particles in the atom.  So, for arsenic, there are 33 protons.  Elements are neutral, so there are also 33 electrons in this atom.  Electrons are the negatively charged particles.  Neutrons are the neutral particles in the atom.  The atomic mass, which is the number underneath the word arsenic, is the added total of the mass of all of the electrons, protons, and neutrons.
The protons and neutrons are clustered together to for the nucleus of the atom.  The electrons travel around the nucleus in paths called orbitals.  But, the atoms are very tiny so you can't see any of this, which means you wouldn't be able to see an arsenic atom if I put it in your tea.
Unlike protons and electrons, neutrons aren't restricted to the atomic number of their element.  It's not uncommon for elements to have more neutrons than electrons.  When this happens it's an isotope of the element.  Isotopes will have a different mass and a different number of neutrons from the original element but the protons and electrons will be the same, making it the same element.
And that's really all anyone needs to know about elements ever.