Chapter 2 Flashcards
Matter
anything that has mass and takes up space
Mass
a measure of the amount of material in an object
Element
a pure substance with unique physical and chemical properties that cannot be broken down into other substances (contains only one type of atom, EX. O, N, Na)
Atom
smallest unit of an element
Proton
positive charge; The atomic number
Neutron
is neutral
Electron
negative; have to balance out protons
Valence electrons
electrons in the outermost shell of an atom
Hydrogen bond
A WEAK chemical bond where the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to a slightly negative atom of polar covalent bond in another molecule (weakest bond)
Ionic bond
a chemical bond resulting from the attraction between oppositely charged ions (weak and easily broken by water).
covalent bond
a type of strong chemical bond in which two atoms share one or more pairs of valence electrons (strongest bond)
molecule
two or more atoms held together by covalent bonds (EX: O2)
compound
substances that contain 2 or more elements in a fixed ratio (EX: H2O and sodium chloride )
molecular formula
chemical symbols and subscripts to indicate the exact numbers of different atoms in a molecule or compound (H2O)
structural formula
indicates the bonding arrangement of the atoms in the molecule (H-O-H)
polar molecule
one with an uneven distribution of charge
Solvent
A dissolving agent of a solution. Water is the most versatile solvent known
Solute
A substance that is dissolved in a solution
Solution
A liquid that is a homogenous mixture of two or more substances
Aqueous Solution
A solution in which water is the solvent
Acids
a chemical compound that releases H+ to a solution (pH below 7)
Bases
a compound that accepts H+ and removes them from solution (pH above 7)
Neutrals
have an equal amount of H+ and OH- groups. They are not corrosive (pH= 7)
What is a buffer?
any compound that tends to accept or release H+ to maintain the pH of a solution
Draw an oxygen atom and label parts (proton, neutron, electrons in its shells)
Describe the difference between a covalent, ionic, hydrogen bond. Which bond is strongest, and which is weakest?
Covalent- strongest
Hydrogen- weakest
Which state of water (gaseous, liquid, solid) is most dense and least dense?
Most dense- liquid
Least dense- gas
Non Polar Covalent Bond
electrons are shared equally
polar covalent bond
electrons are pulled closer to the more electronegative atom.
Dehydration Reactions
(taking apart) Enzymes stress the molecular bond at the active site, causing it to come apart quickly.
Synthesis Reactions
(putting together) Enzymes bring molecules close together at the active site, causing them to react quickly
Hydrolysis
taking apart by adding water
