VIDEO: A teenager mixing chemicals on a stove ended up causing quite a scare at a home in Concord. A person driving by noticed smoke pouring out of a home on Old Bedford Road around 7:45 p.m. Tuesday and called 911. Firefighters found something smoldering in a pot on the stove in the kitchen and quickly put out the fire. Then they realized it wasn’t food that was burning. A teenager told investigators he was mixing chemicals trying to make a putty-like substance that would create different colored smoke when it’s lit. No one was hurt, but the teen and two firefighters were taken to the hospital for evaluation as a precaution. A hazardous materials unit and the State Police bomb squad were called in.