13-Letter Words Matching ___T________C

There are 18 13-letter words that match ___T________C. 2 are common words, such as BACTERIOLOGIC and PHOTOELECTRIC. A rarer one is PROTOHISTORIC. In this set, I is the most frequent open letter (18 words). 4 words contain a doubled letter.

Full list 18

bacteriologicphotoelectricpentasyllabicbacteriolyticbiotelemetrichistaminergiciontophoreticmultimetallicmultiorgasmicmultisyllabicpantisocraticphotobiologicphotogeologicphotoperiodicpostembryonicpostepilepticposttraumaticprotohistoric

About this list

Words
18 (2 common words)
Common example
bacteriologic
Rare example
protohistoric
Doubled letters
4
Ending in S
0
Most frequent letter
I (18)

Questions

How many 13-letter words matching ___t________c are there?

18. 2 of them are common words.

What is a common example?

BACTERIOLOGIC is among the common words in this set.