From "How Science Works"

State of matter of about 99% of all matter in the universe?

plasma

Hardest solid known? (60% harder than normal diamonds.)

lonsdaleite

Most viscous liquid? (used for road surfaces; 20 billion times more viscous than water at the same temperature.)

pitch

Speed at which oxygen molecules move around at room temperature?

1,700 kph

What would happen to superfluid helium if stirred?

it would spin forever

What is the triple point of water? when it can be solid, liquid, and gas at the same time

0.01°C

Avogadro’s law

At the same temperature and pressure, equal volumes of all gases contain the same number of molecules

What is sublimation?

when a substance goes straight from the solid state to a gas

What is ionization?

when, at high energy, electrons separate from their atoms/molecules, producing a plasma

What is recombination?

when plasma changes back to gas

What is the opposite process to evaporation?

condensation

What is the opposite process to sublimation?

deposition

what is latent heat?

the energy released or absorbed by a substance when changing phase

What percentage of a hydrogen atom is empty space?

99%

What is the mass of an electron?

1/2000 the mass of a proton

Atomic number

the number of protons in an atom

What defines an element?

the atomic number

Atomic mass

the combined mass of an atom’s protons, neutrons, and electrons

What unit is used to measure atomic mass?

amu

Relative atomic mass

the average mass of an element’s isotopes

Mass number

the total number of protons and neutrons in an atom

Where does the term “quark” come from?

the novel “Finnegan’s Wake” by James Joyce

What is a quantum?

the smallest possible amount of any physical property (such as energy or matter)