Question

Chemistry in Math due to inactivity in Chem area.

Basic Periodic Table of Elements Question.. MEDAL!

Answer 1

All you need to do is do a search for periodic table.
Or go to wikipedia and look up periodic table.

Answer 2

@calculusxy
If everyone doesn't post in the chemistry section, it will never get busy! So please post it there, and ask for help here with reference to the original post.

If you don't want to google or look up a periodic table, as in a classroom exam, you can find your answer noting that in the periodic table, the atomic numbers are consecutive.
So just put Pb in the right square with reference to Astatine (atomic no. 85) leaving the proper space to fit in elements with atomic numbers 83 and 84.

Answer 3

I think the purpose of the question is to understand the structure of the Periodic Table Rows (Period) and Columns (Groups). At the time is was a breakthrough and guided the discovery of unknown elements and their chemistry.

According to the image we are given Pb has 82 protons which puts it in the same row/period as the noble gas Radon with 86. So that reduces our choice to C &D.

With 82 electrons in a period with 86 electrons for a full shell (Radon is full with 86) it is in the Carbon group so that makes it C.

Checking wikipedia or other sources verifies this. Anyone can look it up, but I think the problem wants you to be able to figure it out using information in the Periodic Table of Elements to appreciate what a cool tool it was especially in an era before the internet.