This is nine-year-old Joshua, from Northern California.
Josh's mother, Kerry, got in touch this week, saying: "My son... has been fascinated by the Periodic Table since he was 4 years old! He has been asked to give several presentations at his school and is very well read on the subject.
"We just found out about your site and Joshua is really excited to have his picture shown, please please please include it on your website!"

I had to ask for the reason behind that, and it was explained.
"He likes to be called Professor Carbon because he dressed up as a scientist for Halloween a couple of years ago. Would you like to see pictures?"
Umm, yes please (see below)!
Kerry further explained: "Joshua is a very clever little boy, not sure if you have heard of it, but he is a 'young scholar' with The Davidson Institute, which is an organization for profoundly gifted children.
"We have a chemisty mentor for him, who has put us in contact with a Professor at UC Davis.
"We have actually been invited on Friday to take a tour of their Lab, which Joshua is very excited about!"
Kerry also said Josh was excited about the upcoming Pi Day on 14 March.
I suggest Professor Carbon keeps a close eye on my Numberphile channel... A Pi extravaganza is planned!