Chemistry Final Review

Chemistry

study of matter

Accuracy

how close a measurement is to the accepted value

Precision

how close a measurement are to each other

Percent Error

accuracy of a measurement

Physical Property

observed without changing identity of substance

Chemical Property

ability of a substance to undergo changes in identity

Periodic Law

repetition of chem/physics properties, arranged by atomic #

Period

row on p. table that classifies elements by # of atomic shells

Group

column on p. table that arrange elements by # of electrons

Octet Rule

states atoms are most stable surrounded by 8 valence electrons

Valence Electrons

electrons in outermost energy level of atom that influence how an element will react with other substances

CER

Claim, Evidence, Reasoning

Protons

positive

Neutrons

zero

Electrons

negative

Protons determine…

the atom’s identity

Isotope

a form of a chemical element where atoms have same # of protons, diff # of neutrons

Metals

left & center of p. table

Nonmetals

upper right corner of p. table

Metalloids

zigzag staircase on p. table

Group 1

alkali metals

Group 2

alkaline earth metals

Group 17

Halogens

Sublevel D

transition metals

Sublevel F

inner transition metals

Group 18

noble gases

Beryllium

(Be)

Calcium

(Ca)

Atomic Radius

increases left & down

Ionization Energy

increases right & up

Electronegativity

increases right & up

Metals e-

form cations, lose e, get smaller

Nonmetals e-

form anions, gain e, get larger

What are the 3 bonds?

ionic, covalent, metallic

Covalent Bonds

form between nonmetal & nonmetal (molecular formula)

Ionic Bonds

form between metal & nonmetal (formula unit)

Why do atoms form chemical bonds?

to become stable

Formula Units

NaCl , CaCl2

Molecular Formula

H2O , CO2

Strongest - Weakest

hydrogen bonding - dipole interactions - dispersion forces