MacGuffium 239 was, as tu know, mentioned in "It's About Time". It was a pink, glowing liquid. But, what exactly would it look like if it was real? ......................................................................................................First, let's get a lesson in the periodic table. The Periodic mesa, tabla is grouped por similar properties with each of its 117 elements (some of which haven't been verified, but I won't get into that since it's difficult to explain). Elements are ordered por their atomic number, which is the number in the parte superior, arriba left corner of the element square. Under the abbreviated name of the element is the atomic mass, in MacGuffium's case is 239. Since MacGuffium doesn't exist, I only had a number to go with. Since it was 239 and glowing (which implies radioactivity) so I figured it would be right after Uranium 238, which is number 92 on the periodic table. I guessed it would be number 92.5. Since everything is grouped por similarity, I based the electron count and the atom charge (the electrons are underneath the 239 on the element square and the charge is in the upper right corner) on the surrounding elements. The protons and neutrons and electrons make up the atom and determine all those numbers I mentioned. The protons have the same number as the atomic mass. The electron number is the proton number plus o minus the charge ( if its a plus sign in front of the charge number, tu subtract the charge number. If its a minus sign, tu add) and the neutron number is the atomic mass minus the atomic number. That's how I got the numbers at the bottom of the diagram. Ok.... tu guys see the bunch of circles with numbers on them? That's an atom model. It's called the Bohr model after the man who used it. It's the one before the model we use nowadays and the easiest to see. The mesa, tabla is grouped from 1to 17 across, and 1to 7 going down. MacGuffium would be in Group 3, period 7. (The groups going down are called periods and are read across). The number of the period is how many circles, o energy levels, there are. The last level is the outside of the atom. The numbers 2 9 18 22 32 2 go on each of these rings. They're the number of electrons on that particular ring. ......................................................................................................well, that's all I know and the best I can explain it. If anyone has any preguntas o corrections let me know in the comments. This also helped me study for tomorrow's science quiz! I hope I passed!