Water and Life

Flashcards covering key concepts from the Water and Life lecture.

Water is the only common substance to exist in the natural environment in ______ physical states of matter.

three

The structure of the water molecule allows it to interact with ______.

other molecules

Polar covalent bonds in water molecules result in ______ bonding.

hydrogen

A water molecule is a ______ molecule because the overall charge is unevenly distributed.

polar

Cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a ______ are four emergent properties of water.

solvent

Cohesion of water molecules helps the transport of water against ______ in plants.

gravity

Surface tension is a measure of how difficult it is to break the ______ of a liquid.

surface

Water has an unusually high ______ tension due to hydrogen bonding.

surface

Water can absorb or release a large amount of heat with only a slight change in its own ______.

temperature

A calorie (cal) is the amount of heat required to raise the temperature of 1 g of water by ______°C.

1

Water’s specific heat is ______ cal/(g • °C).

1

The specific heat of water can be traced to ______ bonding.

hydrogen

Evaporation is the transformation of a substance from ______ to gas.

liquid

As a liquid evaporates, its remaining surface ______, a process called evaporative cooling.

cools

Ice floats in liquid water because hydrogen bonds in ice are more ______, making ice less dense than water.

ordered

Water reaches its greatest density at ______°C.

4

Water is a versatile ______ due to its polarity.

solvent

Water can dissolve compounds made of nonionic ______ molecules.

polar

A hydrophilic substance is one that has an ______ for water.

affinity

An acidic solution has pH values less than ______.

7

A base is a substance that ______ the H+ concentration of a solution.

reduces

Strong acids and bases dissociate completely in ______.

water

The internal pH of most living cells is close to ______.

7

Buffers are substances that minimize changes in concentrations of H+ and ______ in a solution.

OH–

Ocean acidification occurs when CO2 dissolves in seawater forming ______ acid.

carbonic

An atom is the smallest unit of ______ that still retains the properties of an element.

matter

Atoms are composed of ______ particles including neutrons, protons, and electrons.

subatomic

An element’s atomic number is the number of ______ in its nucleus.

protons

Isotopes are atoms of an element that differ in number of ______.

neutrons

Radioactive isotopes decay ______, giving off particles and energy.

spontaneously

A molecule consists of two or more ______ held together by covalent bonds.

atoms

A covalent bond is the sharing of a pair of valence ______ by two atoms.

electrons

Electronegativity is an atom’s attraction for the ______ in a covalent bond.

electrons

An ionic bond is an attraction between an ______ and a cation.

anion

Compounds formed by ionic bonds are called ______ compounds, or salts.

ionic

Hydrogen bonds form when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another ______ atom.

electronegative

Van der Waals interactions are attractions between molecules that are close together as a result of ______ charges.

temporary

A molecule’s size and ______ are key to its function.

shape

Chemical reactions are the making and breaking of ______ bonds.

chemical

The starting molecules of a chemical reaction are called ______.

reactants

Sunlight powers the conversion of carbon dioxide and water to ______ and oxygen.

glucose

Chemical equilibrium is reached when the forward and reverse reactions occur at the same ______.

rate

The ______ system is used to take measurements in all science classes.

metric

The ______ variable is the variable that changes as a result of the independent variable.

dependent

A controlled experiment means that only ONE independent variable is being tested at a ______.

time

To visualize quantitative data, graphs such as line graphs, bar graphs, and ______ graphs are used.

pie

The concluding paragraph should restate the problem statement, hypothesis, and accept or reject the ______.

hypothesis