After competing his project for the Meneley Elementary School science fair, sixth-grader Cole Craighead now cleans the doorknobs in his house more often.
The 11-year-old scientist tested how much bacteria grows on door knobs.
"It turned out pretty good. The first week the bacteria didn't grow much. The third week there was mild bacteria," he said. "I learned bacteria grows quickly because people have dirty hands. I'm kind of a germaphobe sometimes so I didn't really enjoy the project."
Cole's project was one of 240 entered in the fair which included fourth through sixth grade, and one first-grade class project. Hypotheses tested included what works best to get rid of stinky feet, what fabric absorbs the most dye and how colors affect emotions.
"The world needs more problem-solvers, and with the new science, technology, engineering math focus we need children understanding the inquiry process," fifth-grade teacher Cathy Hackler said. "Science makes children question the world around them, and a lot of times it can debunk misconceptions."
Retired teacher Mike Jessup served as a judge at Tuesday's fair and remembered being a part of the school's first science fair more than a decade ago.
"Being here as long as I have, I've been able to see the progression of students involved, and the quality of the projects," he said. "Students need to understand the process is not just limited to science, it's a problem-solving process that can be applied to life."
Dalton Turley, 11, asked how soap reacts if it floats.
He microwaved Ivory soap, which floats in water, and Irish Springs, which sinks, and tested which expanded more.
Dalton discovered Ivory soap expanded more in the microwave.
"I liked putting soap in the microwave the most because it was fun to watch," he said. "I love science because you get to do a lot of stuff you don't normally get to do."
Judge Richard Kizer was impressed with the experiment.
"I've been doing this 12 years, and I've never seen anything come close to that," he said. "It was really unique."
By the end of his inquiry, 11-year-old Chandler Harwood discovered his hypothesis that lemon-lime soda freezes faster than orange or cola was incorrect.
"At first I thought lemon-lime would freeze faster, but cola actually freezes faster. I think caffeine helped it freeze faster," Chandler said. "I enjoyed when we got to look at the soda every hour, and see the changes. It was a hard process having to hear the timer and get to it."
The top seven science projects will move on to the regional competition in Reno in March 2013.