Now before we talk about the periodic table, the elements and their symbols, let's go over a little bit of history we're going to see here. At the end of the 18th century, it was Antoine Libersoire who compiled a list of 23 elements and their symbols known at the time. And in 1869, it was Mendeley who organized them by their recurring or periodic chemical properties. He used the term periodic law to justify the way he organized the elements.
Now, how does this connect to the periodic table? Well, the periodic table here has all of these elements with their symbols. And we're going to see the periodic table itself can be seen as a grid of elemental symbols that is organized in terms of increasing atomic number. Remember, your atomic number uses the variable Z, and it basically tells us the number of protons for any particular element. So here hydrogen has the lowest atomic number, and as we start moving, we'll see that the atomic number is increasing, so 1, 2, 3, so on and so forth.
By organizing the periodic table in terms of increasing atomic number, elements are allowed to fall within certain columns or groups. When they're in the same group, they're going to share similar chemical properties. This was the genius of Mendeley. By organizing it in terms of increasing atomic number, he could predict that in this slot an element would be found eventually. So although there were about 23 elements at the time when they started organizing this, by organizing in the way that they did, they could predict that other elements would be found over time.
Now the element symbol itself is just the abbreviated form of an element. Now most elements it's based on the first letters of their names. Hydrogen starts with an H, so its element symbol is an H. Lithium starts with Li, so with element symbol as Li. But there are 11 elements on the periodic table which aren't based on the first level letters of their name, but actually based on their Latin names. Now, the Latin names are not as important, but it's good to know that certain names and certain symbols don't really match up too well. That's because the symbol is based on the old Latin name that has been replaced over time with this new modern one.
So those elements include Sodium which is Na, Potassium which is K, Iron which is Fe, Tungsten which is W, Copper which is Cu, Silver which is Ag, Gold which is Au, Mercury which is Hg, Tin which is Sn, Lead which is Pb, and then finally Antimony which is Sb. The rest of the elements, for the most part we can see that the name comes from the first letter or first few letters of the name. But these 11, these special 11 ones, their symbol comes from the old Latin name that has been replaced over time.
So just remember the periodic table can be credited from Lavis or Mendeleev. Organizational wise, Mendeleev had a big part in playing when organizing the periodic table, and it's organized in terms of increasing atomic number so that groups that have similar chemical properties, more elements that fall in certain groups have similar chemical properties. So take this to heart when you're learning about each of these elements. Now we'll consult with your professor because normally they want you to memorize a set number of elements with their symbols. So I would go back and talk to your professors and find out how many of these elements you do need to know from memory.
