3A-Brendan+Halse-+Melting+and+boiling+point

The periodic table is one of the most important documents that is used in chemistry today. This is due to that fact that it has a list of all known elements and has them ordered in such a way so that just by looking at the different positions of elements on it we can understand how the elements are likely to react with one another. Because of this there are trends that appear on the periodic table. The trend I will be looking at will be the trend in melting and boiling points of elements on the periodic table. At a first glance the melting points of the elements may appear to be ordered randomly but upon closer inspection there are trends within smaller subsections of the periodic table.

**A closer look at the periodic table**
====This as I'm sure most of you are aware is the periodic table. Now if we have a closer look just above the periodic table you will see that there three main groups that the periodic table is split into. They are Metals, Nonmetals. and Metalloids. Then if we look closer we can see that there are still more ways to split the periodic table up. Under the heading of Metals there are Alkali Metals, Alkaline Earth Metals, Lanthanoids, Actinoids, Transition Metals, and Post Transition Metals. Under the heading Nonmetals there are Halogens, Noble Gases, and Other Nonmetals. Now as i said earlier the trends only appear when we look at smaller subsections of the periodic table. So we will start by looking at the trends in the Alkali Metals.====


 * Alkali Metals**
 * **Chemical symbol** || **Melting point °C** || **Boiling point °C** ||
 * Lithium || 180.5 || 1317 ||
 * Sodium || 97.8 || 892 ||
 * Potassium || 63.7 || 774 ||
 * Rubidium || 39 || 688 ||
 * Caesium || 28.4 || 690 ||
 * Francium || 27 || 677 ||

lkali Metals category. From this data we can say that there is a downward trend in the melting an boiling points the more we go down the table, that is, as the ato
====mic number increases the melting and boiling points of the metals decreases. The reason for this is because in metals bonding is due to a nucleuses attraction to the sea of electrons. In the larger atoms the nucleus is further from the sea of electrons so attraction is weaker which ultimately means the bonds are weaker so the heat energy required to break those bonds is less. Next Alkaline Earth Metals.====

**Alkaline Earth Metals**

 * < **Chemical symbol** ||< **Melting point °C** ||< **Boiling point °C** ||
 * < Beryllium ||< 1278 ||< 2970 ||
 * < Magnesium ||< 648.8 ||< 1107 ||
 * < Calcium ||< 839 ||< 1487 ||
 * < Strontium ||< 769 ||< 1384 ||
 * < Barium ||< 725 ||< 1640 ||
 * < Radium ||< 700 ||< 1140 ||

Again above is a table showing the melting and boiling points, this time, of the
====Alkaline Earth Metals. Looking at melting points aside from Magnesium there is a trend that as atomic number goes up melting point goes down. The reason magnesium falls outside the norm is that while it is still a metal it bonds slightly differently which results in it having a slightly weaker bond, which results in a low melting and boiling point. However if we look at boiling point we can see that there is no exact trend here instead if we put a line of best fit into the graph we can see that the overall trend is the same. It would seem appropriate to say that as the atomic number goes up that the meting and boiling point go down however it would be silly to say this is totally true because melting fluctuates quite a bit the only reason I can make this general statement is because the line of best fit would make that kind of a shape. From what I know and have read I would like to say that the structure of the bonds is what is causing this difference however I do not know. Next up is Transition Metals.====

Seeing as the Transition Metals group takes up such a large portion of the periodic table I will only show information regarding the 4th period Transition Metals.

 * **Chemical symbol** || **Melting point °C** || **Boiling point °C** ||
 * Scandium || 1539 || 2832 ||
 * Titanium || 1660 || 3260 ||
 * Vanadium || 1890 || 3380 ||
 * Chromium || 1857 || 2482 ||
 * Manganese || 1244 || 2097 ||
 * Iron || 1535 || 2750 ||
 * Cobalt || 1495 || 2870 ||
 * Nickel || 1453 || 2732 ||
 * Copper || 1083.5 || 2595 ||
 * Zinc || 419.6 || 907 ||

====So looking at the data it isn't really obvious what sort of trend is occurring here, however if we look at the graph we can see that the melting and boiling point peaks sort of near the middle where there is a dip then the pattern goes back to normal. Now ignoring the anomaly at chromium and manganese this graph is sort of like a parabola shape. This parabola shape is continued all the way down the group that is it is pretty much the same in period 5 and 6 but I cant be certain for period 7 as the data table I have used doesn't have any information on them. I can't say why this pattern occurs but I assume it has something to do with the way the metals bond in different groups. Oh yes it is worth noting that the melting and boiling points of the Transition Metals goes up as you go down, as the period number increases, this is because the atoms are larger so the sea of electrons is bigger meaning bonds are stronger and thus melting and boiling point go up. Next up Lanthanoids and Actinoinds.====

**Lanthanoids and Actinoids**
====The Lanthanoids and the Actinoids are two special groups that exist on the periodic table between period 6 and 7 Alkaline Earth Metals and Transition Metals. Because of their strange position trends in these two sections are rather difficult to spot, so difficult that I don't think there are any trends and for that reason this section will be very short. To illustrate my point here is a graph of the melting and boiling points of the Lanthanoids. And moving forward it is time to look at Nonmetals and to start off we will look at the Noble gasses.====

**Noble Gases**
====As we look at the table and graph we can see that going down the group or as the atomic number increases the melting and boiling point goes up as well. This is due to intermolecular attraction between the molecules which is known as van der Waals dispersion forces. I could go on to explain it but I think that a youtube video would be better. Just as an after thought I'll say that ununoctium was left out because we don't know much about it.====
 * **Chemical symbol** || **Melting point °C** || **Boiling point °C** ||
 * Helium || -272.2 || -268.9 ||
 * Neon || -248.7 || -246.1 ||
 * Argon || -189.4 || -185.9 ||
 * Krypton || -156.6 || -152.3 ||
 * Xenon || -111.9 || -107 ||
 * Radon || -71 || -61.8 ||

**Halogens**
====If we look at the table above and it is quite easy to see that the same thing is happening here as with the Noble gases and then the graph makes it even more obvious. Again this is to do with the van der Waals dispersion forces. If you watched the video and still cant work out why the boiling point rises as the atom or molecule gets bigger, lets just say because there are more electrons and more protons in the larger atoms the charges are bigger thus the effect of slight changes is more noticeable which creates larger attraction forces. Now that all of that has been explained we will do an overview and I will explain why I missed what I missed, namely the Post Transition Metals, the Other Nonmetals, and the Metalloids.====
 * Chemical symbol || Melting point °C || Boiling point °C ||
 * Fluorine || -219.6 || -188.1 ||
 * Chlorine || -101 || -34.6 ||
 * Bromine || -7.3 || 58.8 ||
 * Iodine || 113.5 || 184.4 ||
 * Astatine || 302 || 337 ||

**Conclusion**

 * 1) ====Alkali Metals melting and boiling points decrease as atomic number increases====
 * 2) ====Alkaline Earth Metals similar thing with melting point but no pattern with boiling point====
 * 3) ====Transition Metals melting and boiling points increase to about group 5/6 where they start to decrease, and they increase as period number increases====
 * 4) ====No pattern in the Lanthanoids or Actinoids====
 * 5) ====Noble Gases melting and boiling points increase as atomic number increases====
 * 6) ====Halogens are like the Noble Gases but at higher temperatures====

====The reason I didn't say anything about the remaining groups is because they all exist in virtually the same areas and to do them separately would be very difficult not to mention that to find any sort of pattern would be nigh on impossible. I could have done these together however the fact that they are al parts of different groups means trying to make sense of it all would become ridiculous, therefore I haven't said anything on it.====