Molecular Structure & Bonding
States of Water, Density & Heat
Cohesion, Viscosity & Water as a Solvent
Physical Properties of the Ocean
Chemistry of the Sea
100

This is the special type of bond that forms between water molecules because of their opposite charges.

What is a hydrogen bond?

100

This is the process by which liquid water molecules break free of hydrogen bonds and enter the gas phase.

What is evaporation?

100

This is the term for particles of the same substance sticking together.

What is cohesion?

100

This color of visible light penetrates the deepest into the ocean.

What is blue?

100

Salinity is often expressed in these units — grams of salt per 1,000 grams of seawater.

What are parts per thousand (‰)

200

Water molecules are described using this term, because the oxygen and hydrogen ends carry weak, opposite charges.

What is "polar"?

200

This is the temperature at which fresh water reaches its maximum density.

What is 4°C?

200

This property, caused by strong cohesion at the water's surface, allows organisms like water striders to walk on water.

What is surface tension?

200

This is the amount of additional pressure (in atmospheres) added for every 10 meters of ocean depth.

What is 1 atmosphere?

200

This principle, discovered by chemist William Dittmar, states that the relative proportions of major ions in seawater stay constant even as total salinity varies.

What is the rule of constant proportions?

300

This is the number of hydrogen atoms and oxygen atoms found in a single water molecule.

What is two hydrogen atoms and one oxygen atom?

300

This is the term for the fixed, three-dimensional pattern that water molecules lock into when they move slowly enough for hydrogen bonds to hold them in place — in other words, when water freezes.

What is a crystal?

300

This term describes a liquid's resistance to flow

What is viscosity?

300

Because water is denser than air, sound travels about this many times faster in water than in air

What is 4.5 times?

300

This gas makes up more than 80% of the dissolved gas in the ocean, compared to less than 0.04% of the atmosphere.

What is carbon dioxide (CO2)?

400

This is the term for two or more atoms bonded together chemically.

What is a molecule?

400

This is the term for the amount of energy required to raise a given mass of a substance by one degree Celsius.

What is specific heat?

400

Because it can dissolve more substances than any other natural substance, water has earned this nickname.

What is the universal solvent?

400

This region of the ocean allows low-frequency sound waves to travel uninterrupted for thousands of kilometers.

What is the Deep Sound Channel?

400

This is the term for the ongoing drop in ocean pH caused by the ocean absorbing excess atmospheric CO2.

What is ocean acidification?

500

This is the approximate total number of known elements in nature.

What is 118?

500

This is the term for the cooling effect that happens when only the fastest, highest-energy molecules escape into vapor, lowering the average energy of the molecules left behind.

What is evaporative cooling?

500

When table salt dissolves in water, it separates into a positive sodium ion and this negatively charged ion.

What is a chloride ion (Cl⁻)?

500

This is the approximate depth at which even blue light is fully absorbed in the clearest ocean water, beyond which it is completely dark.

What is 1,000 meters?

500

This is approximately how much the ocean's pH has already dropped due to fossil-fuel CO2 emissions.

What is 0.1 pH units?