AP Biology Obj 2A, 2B, 3A, 3B (Unit 1 Chemistry of Life)

What are protons, electrons, and neutrons?

Protons are positively charged particles located in the nucleus of an atom, electrons are negatively charged particles that orbit the nucleus, and neutrons are neutral particles also found in the nucleus.

What is the atomic number?

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

What is the mass number?

The mass number is the total number of protons and neutrons in an atom's nucleus.

What is an isotope?

An isotope is a variant of an element that has the same number of protons but a different number of neutrons, which can make some isotopes radioactive due to instability.

What are covalent bonds?

Covalent bonds are chemical bonds formed when two atoms share one or more pairs of electrons.

What is the difference between nonpolar and polar covalent bonds?

Nonpolar covalent bonds occur when electrons are shared equally between atoms, while polar covalent bonds occur when electrons are shared unequally, leading to partial charges.

What are ionic bonds?

Ionic bonds are formed when one atom transfers electrons to another atom, resulting in the attraction between positively and negatively charged ions.

When do hydrogen bonds form?

Hydrogen bonds form when a hydrogen atom covalently bonded to an electronegative atom is attracted to another electronegative atom.

Are hydrogen bonds stronger or weaker than covalent and ionic bonds?

Hydrogen bonds are generally weaker than both covalent and ionic bonds.

What is the structure of water?

Water is a polar molecule with a bent shape, consisting of one oxygen atom covalently bonded to two hydrogen atoms.

What is cohesion?

Cohesion is the tendency of molecules of the same substance to stick together, which is particularly strong in water due to hydrogen bonding.

What is adhesion?

Adhesion is the tendency of molecules of different substances to stick together, such as water molecules adhering to plant cell walls.

What is surface tension?

Surface tension is the cohesive force at the surface of a liquid that makes it behave like a stretched elastic membrane.

What is specific heat?

Specific heat is the amount of heat required to raise the temperature of a substance by one degree Celsius, and water's high specific heat helps regulate temperature in organisms and environments.

Why does ice float?

Ice floats because it is less dense than liquid water due to the formation of a crystalline structure that spaces water molecules further apart.

What is a solute?

A solute is a substance that is dissolved in a solvent to form a solution.

What is a solvent?

A solvent is a substance that dissolves a solute, resulting in a solution.

What is a solution?

A solution is a homogeneous mixture formed when a solute is dissolved in a solvent.

How do acids and bases affect hydrogen ion concentration?

Acids increase the hydrogen ion concentration in a solution, while bases decrease it.

What do buffers do?

Buffers help maintain a stable pH in a solution by neutralizing small amounts of acids or bases.