Basic chem

which elements make up 96% of living matter

CHNOPS

hydrogen
phosphorus
nitrogen
oxygen
sulfur
- more than 100 elements have been identified (92 naturally occurring), and about 25 are known to be essential to life with variation)
- CHONmake up 96% of living matter
- CA, P, K, S, NA, CL, Mg-4% trance elements=> required in minute quantities (ex, Fe, I, Zn, B)

Atomic Mass

atoms have an atomic mass (mass number)

Isotopes

the atoms of elements may have different mass numbers
- why?
- oxygen - 16

Radioisotopes

the nuclei of many isotopes are unstable and radiate energy

Equal or Unequal sharing (most important concept) (go on YouTube and review)

electrons in covalent bonds can be shared equally or unequally

form fits function

heat vaporization

solvent of life - water, it will only dissolve water, like dissolves like

polar

Molecule with partial charges. Unequal sharing. Soluble in water.

electronegativity

Attraction of an atom for the electrons of a covalent bond.

adhesion

The attraction of unlike molecules - typically involving hydrogen bonds..

solute

Substance dissolved in a solution.

solvent

Dissolving agent of a solution.

ions

Charged atoms caused by an imbalance of electrons and protons

capillary action

A process powered by adhesion that causes water molecules to move upward through a narrow tube such as the stem of a plant.

Heat capacity/specific heat

the amount of thermal energy that must be absorbed or lost for 1 g of a substance to be changed 1 degree C.

alkaline

a basic substance; chemically, a substance that absorbs hydrogen ions or releases hydroxyl ions; in reference to natural water, a measure of the base content of the water.

surface tension

An inward force that tends to minimize the surface area of a liquid; increases the difficulty of breaking the surface of a liquid.

heat of fusion

the amount of energy required to change a 1 g of a substance from the solid phase to the liquid phase.

hydrophobic

insoluble in water

hydrophilic

having a tendency to mix with, dissolve in, or be wetted by water.

covalent bonds

Bonds created by sharing electrons with other atoms.

ionic bonds

Bonds between atoms that are created by the transference of electrons.

hydrogen bonds

Very weak bonds; occurs when a hydrogen atom in a polar covalent molecule is attracted to another atom of a polar covalent bond.

nonpolar

No partial charges. Not soluble in water. Equal sharing

heat of vaporization

The amount of energy a liquid must absorb for 1 g to be converted to a gas.

polar covalent bond

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

boiling point

The temperature at which a liquid changes to a gas

acid

A substance that increases the hydrogen ion concentration of a solution.

cohesion

Linking together of like molecules - typically with hydrogen bonds.

base

A substance that decreases the hydrogen ion concentration in a solution.

pH scale

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14. O is most acidic + and 14 is most basic + or alkaline.

anion

A negatively charged ion

buffer

A solution that minimizes changes in pH when extraneous acids or bases are added to the solution.

transpiration

The process by which water is lost through a plant's leaves

evaporative cooling

The process in which the surface of an object becomes cooler during evaporation, owing to a change of the molecules with the greatest kinetic energy from the liquid to the gaseous state.