Brass doorknobs automatically disinfect themselves in about 8 hours.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Aluminum used to be more valuable than gold!
84
Most dust particles in your house come from dead skin.
48
One gallon of used motor oil can ruin approximately one million gallons of fresh water!
71
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
One 75-watt bulb gives more light than three 25-watt bulbs.
57