A single speck of dust is half way in size between a subatomic particle and the Earth.
15
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101
Iron weighs more after it rusts.
16
A ball of glass will bounce higher than a ball made of rubber.
73
The bark of an older redwood tree is fireproof.
65
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108