electron pair acceptor
electron pair donor
activation energy, Ea
minimum energy required in order for the reactants to collide with sufficient energy to break the bonds in the reactants so the products can form
rate of reaction
decrease in the concentration of reactants per unit time or the increase in the concentration of products per unit time.
the enthalpy of the products is less than that of the reactants, a reaction will lose energy, primarily as heat to its surroundings
the enthalpy of the products is greater than that of the reactants, a reaction will absorb energy as heat from its surroundings.
heat energy transferred under standard conditions, pressure 101.3 kPa, temperature 298 K. Only ∆H can be measured, not H for the initial or final state of a system.
Average bond enthalpy
The amount of energy required to break one mole of bonds in the gaseous state averaged across a range of compounds containing that bond
the ability of an atom to attract a pair of electrons in a bond. increases across a period and down a group.
first ionization energy
the minimum energy required to completely remove the first electron from one more of gaseous atoms. involves a transition of an electron from its ground state n=1 energy level to n= infinity.
mass number (A)
the total number of protons and neutrons in one atom of an element
atomic number (Z)
the number of protons in one atom of an element
isotopes of an element
atoms of the same element with a different amount of neutrons and subsequently different masses. they have the same chemical properties but different physical properties
has all seven frequencies of light. ex. a rainbow
shows the colors shown as a result of energy being released from an atom after it is excited
relative atomic mass (Ar)
the weighted mean mass of the masses of the naturally occurring isotopes of an element relative to one atom of 12-C
relative molecular mass (Mr)
the average mass of a molecule compared to one atom of 12-C
The simplest whole number ratio of the atoms of each element in a compound.
The integer multiple of the empirical formula. E.g. if the empirical formula is CH the molecular formula could be C2H2.
substance being dissolved
the substance that the solute is dissolved in
Homogenous mixture of two or more substances; a solute and solvent.
The amount/moles of substance contained within a given volume of solution. Symbol c or [ ].
the electrostatic attraction between a pair of electrons and positively charge nuclei. Formed as a result of electron sharing.
refers to covalent, ionic and metallic structures where the exact number or moles of atoms is not definite. Also called a network, crystalline or lattice structure.
characteristics of giant structures
strong intramolecular forces between the particles and weak or no intermolecular forces.
strongest type of intermolecular force formed between polar covalent molecules that contain covalent bonds where hydrogen is bonded to fluorine (H-F), hydrogen is attached to nitrogen (H-N) and hydrogen is attached to oxygen (H-O).
an electrostatic attraction or force between oppositely charged ions
electrostatic attraction between a lattice of positive ions and delocalized electrons
when a substance can be beaten or bent into shape without breaking.
permanent dipole forces
medium strength intermolecular forces formed between polar covalent molecules.
Van der Waals forces
very weak temporarily induced dipole intermolecular forces formed between non-polar covalent molecules.
atoms arranged in different ways, giving rise to different forms of the element. For example carbon atoms can be arranged in three different ways giving rise to diamonds, graphite and fullerenes.