CHEM 101 - basics

atom

basic building block of matter

element

type of atom (eg K)

compound

2+ elements chemically bonded in a fixed ratio

mixture

substances physically combined

extensive properties

extensive amounts WILL change it (eg mass and density)

Intensive Property

constant NO matter size of sample

macroscopic property

can observe w/out considering atomic or molecular scale of matter

potential energy

measures stability, more negative = more stable

King

Kilo, 1000, 10³

Henry

Hecto, 100, 10²

Daughter

Deka, 10, 10^1

Drinks

deci, .1, 10^-1

Chocolate

Centi, .01, 10^-2

Milk

milli, .001, 10^{-3}

Until

Micro, .000001, 10^{-6}

Nine

nano, .000000001, 10^{-9}

Pm

Pico, .000000000001, 10^{-12}

Fuck

femto, f .000000000000001, 10^{-15}

Diatomic elements def

by themselves in nature 2 atoms are bonded together

diatomic elements

H₂,  N₂,  F₂, O₂,  I₂, Cl₂,  Br₂

diatomic element memory trick

have no fear of ice cold beer

Metric Memory Trick

The Giant Monster King Henry Died Drinking chocolate Milk Until Nine Pm Fuck

The

tera, T, 10^12

Giant

giga, G, 10^9

Monster

Mega, M, 10^6

Order of Exponential Numbers in Metric

12, 9, 6, 3, 2, 1, -1, -2, -3, -6, -9, -12, -15

How to count sig figs

all non zero count, leading zero right of decimal dont, zeros between digits count

The Nuclear Atom

dense nucleus contains protons and neutrons (majority of mass) & surrounded by a cloud of electrons (majority volume)

Neutrons

electrically neutral ( 1amu) ; A(mass) - #protons

Protons

in nuclei of atoms has positive charge ( 1amu) , number of protons define element ; atomic number (z)

Electrons

negative charge (really small) and orbit around the nucleus, balancing the positive charge of protons ; Protons - Charge

isotopes

atoms of same element that contain same number of protos but differenet number of neutron

Atomic Mass (u)

how many protons + neutrons are inside that ONE atom

Average atomic mass

weighted average of the masses of all elements isotopes (doesn’t count particles inside)

Natural Abundance (a)

proportion ( %) of each isotope of an element that occurs naturally in a sample