Nodes and Bonds

1. Which letter replaces the question mark? 2. Where can #10 be placed in this diagram? 3. Not a double bond from one node to another here. But where is L? • Do we need to replace the first "?" with a letter or number? Mar 9 '17 at 12:30
• Is 'letter' correct for 1? Mar 9 '17 at 12:33
• Letter is correct Mar 9 '17 at 12:34
• You can also replace it with a number, but that would be a bit more obvious. Mar 9 '17 at 12:35
• The number missing from 1 is 6. The title implies the letter might be C, but I don't feel good about it. Mar 9 '17 at 12:54

1. Which letter replaces the question mark?

Each bond gives the number of letters in common and in the same position for chemical elements given by their atomic number.

For example 1~2 = Hydrogen ~ Helium have 1 bond in common
while 1 ~ 7 = Hydrogen ~ Nitrogen have 5 - Thanks to David Starkey

So number 6 is correct. It has the correct number of bonds since it has one letter in common position with each of the linked atomic numbered elements
Carbon (6)
Hydrogen (1)
Oxygen (8)
Boron (5)
Beryllium (4)
Nitrogen (7)

So thanks to Ian McDonald the number 6 can be represented by letter C for Carbon

2. Where can #10 be placed in this diagram?

This time each bond gives the number of letters in common and in the same position for numbers spelled as words.

For example the bonds with number seven are
Seven
Nine
Three
Five
Six

So the diagram with 10 would be 3. Not a double bond from one node to another here. But where is L?

Each link gives the letters in common position with letters given by the phonetic alphabet - with version A for Alpha and J for Juliett which may vary.

So L is for Lima and the only letter it has a common one with is Kilo so L has one bond to K

This answer was found by user who gave it in an earlier comment - thank you! - I have missed your user name at moment.

• Hydrogen ~ Nitrogen should be 5, right? Mar 9 '17 at 15:44
• Thanks @DavidStarkey - you are absolutely right. I will edit - and it is 5 bonds.
– Tom
Mar 9 '17 at 15:46
• Technically, the NATO phonetic alphabet spells the first one "ALFA", which would also share the A of LIMA. Mar 9 '17 at 16:31