The only elements that are liquid at room temperature are bromine and mercury. However, you can melt gallium by holding a lump in the warmth of your hand.
Unlike many substances, water expands as it freezes. An ice cube takes up about 9% more volume than the water used to make it.
If you pour a handful of salt into a full glass of water, the water level will actually go down rather than overflowing the glass.
There is about 1/2 lb or 250 g of salt (NaCl) in the average adult human body.
A pure element can take many forms. For example, diamond and graphite both are forms of pure carbon.
The chemical name for water (H2O) is dihydrogen monoxide.
The only letter that doesn't appear on the periodic table is J.
Lightning strikes produce O3, which is ozone, and strengthen the ozone layer of the atmosphere.
The only two non-silvery metals are gold and copper.
Although oxygen gas is colorless, the liquid and solid forms of oxygen are blue.
The human body contains enough carbon to provide 'lead' (which is really graphite) for about 9,000 pencils.
Hydrogen is the most abundant element in the universe, while oxygen is the most abundant element in the earth's atmosphere, crust, and oceans (about 49.5%).
The rarest naturally-occurring element in the earth's crust may be astatine. The entire crust appears to contain about 28 g of the element.
Hydrofluoric acid is so corrosive that it will dissolve glass. Although it is corrosive, hydrofluoric acid is considered to be a 'weak acid'.
One bucket full of water contains more atoms than there are bucketfuls of water in the Atlantic ocean.
Approximately 20% of the oxygen in the atmosphere was produced by the Amazon rainforest.
Helium balloons float because helium is lighter than air.
Bee stings are acidic while wasp stings are alkaline.
Hot peppers get their heat from a molecule called capsaicin. While the molecule acts as an irritant to mammals, including humans, birds lack the receptor responsible for the effect and are immune to the burning sensation from exposure.
Dry ice is the solid form of carbon dioxide, CO2.
Liquid air has a bluish tint, similar to water.