chapter 2

electrons

• Being shared or transferred between atoms

• Leads to the formation of chemical bonds

covalent bonds

• chemical bonds formed by the sharing of electron pairs between atoms

• strong, hard to break

ionic bonds

• chemical bond that forms between oppositely charged ions, resulting from the transfer of electrons between atoms

• weak, easy to break

polar bonds

created when there is unequal sharing of electrons

nonpolar bonds

created when atoms share the electrons equally

water polarity

• a positive charge on the hydrogen pole and a negative charge on the oxygen pole

• polar

polar molecule

molecule with an uneven distribution of charge resulting in one side being positive and the other side negative

nonpolar molecule

• a molecule where electrons are shared equally between atoms

• do not have any electrical charges or partial charges

hydrogen bond

a weak attraction between a hydrogen atom (with a partial positive charge) and a highly electronegative atom (like oxygen, nitrogen, or fluorine)

hydrophilic

molecules or substances that are attracted to and readily interact with water

hydrophobic

repelling or not mixing with water

solution

• homogeneous mixture of one or more substances dissolved in a liquid

• solute particles are evenly dispersed

solute

the substance that dissolves in another substance

solvent

a substance, usually a liquid, that dissolves other substances (solutes) to form a solution

colloid

• particles suspended in another medium.

• larger particles that stay afloat

suspension

particles are dispersed within a liquid but not dissolved, leading to the eventual settling of these particles over time

emulsion

a mixture of two or more liquids that don't normally mix (immiscible liquids)

atp in energy transfer

• “fully charged” phosphates

• transferring a phosphate group to another molecule

adp in energy transfer

• loses phosphates

• process requires energy and stores it for later use. 

acid

donates a proton (hydrogen ion, H+) or accepts a pair of electrons

base

a substance that can accept protons (hydrogen ions) or donate electrons

hydrogen ion

a hydrogen atom that has lost its electron, resulting in a positively charged particle

pH

• a scale that measures how acidic or basic (alkaline) a solution is

• ranges from 0 to 14

pH and concentration of hydrogen ions

• hydrogen ions increases, the pH decreases

• hydrogen ions decreases, the pH increases

acidic

pH less than 7

basic

pH greater than 7

neutral

pH of 7

properties of salt

• ionic compounds formed through a reaction between an acid and a base

• composed of cations and anions

properties of acid

• corrosive and can react with metals to produce hydrogen gas

• electrolytes: conduct electricity when dissolved in water

• sour taste

properties of bases

• feel slippery/soapy

• bitter taste

buffer

• a solution that resists changes in pH when small amounts of acid or base are added

• maintains stable pH by neutralizing added acid or base. 

dissociation

process where a compound, molecule, or ionic substance breaks apart into smaller constituents like ions, atoms, or radicals

dissociation and anions/cations

• produces both anions and cations

• e.g. HCl dissolving in water

dissociation and strength of an acid/base

• Strong acids and bases dissociate completely, breaking apart into ions nearly 100% in solution.

• Weak acids and bases partially dissociate, resulting in a lower concentration of ions in the solution.