Chemistry Quiz

Avogadro's number is huge! The reason chemists use 6.02 x 10^23 to define a unit is to avoid having to work with crazy-large numbers.

Sulfur is a nonmetal. It's yellow and lacks a metallic luster.

The average adult human body contains about 250 grams of salt, which is just over half a pound. If you don't have enough salt, your body suffers an electrolyte imbalance called hyponatremia.

Most of the body's iron is locked up in the hemoglobin found in red blood cells, used for oxygen transport.

Water is good old H 2 O!

Milk is close to a neutral pH, but it's slightly acidic thanks in part to the lactic acid it contains.

Ag stands for argentum, which is an old name for silver. The term "argent" survives, meaning silvery.

Mendeleev (sometimes spelled Mendeleyev) is credited with creating the modern periodic table, although his table was based on increasing atomic mass rather than atomic number. Mendeleev's table grouped elements according to common properties and periodic trends.

A liquid takes the shape of its container (no defined shape), but has a fairly constant volume (at least compared to a gas). The state of matter of a substances is due to the kinetic energy of its components. With enough energy, atoms and molecules are less strongly bound to each other.

One interesting property of water is that it achieves maximum density as a liquid, not as a solid. So, ice is less dense than water and floats. When it melts, it becomes more dense. More mass per unit volume means the level of the liquid drops slightly.

Chlorine is not a noble gas. It's one electron shy of a full octet, so unlike the noble gases, it's highly reactive.

You'll find keratin primarily in your hair, nails, and skin, but the most abundant protein in humans is collagen, which is found in bone and cartilage. Both proteins are strong and flexible.

Most of the hydrogen in the world is protium (one proton, no neutrons), but some deuterium and tritium occurs, too. Tritium is radioactive. Deuterium is not radioactive and is the form of hydrogen found in heavy water.

Not all compounds that contain carbon are organic. An example of an inorganic carbon compound is carbon dioxide. All organics contain both carbon and hydrogen. A quasi-exception would be carbon tetrachloride, which is an organic solvent. It's not actually organic, but it is nonpolar so it dissolves organic molecules.