Chemistry test 1

Multiplication/division rule

The result should carry the fewest significant figures from the measurements used in the calculation.

Addition/subtraction rule

Stack all the numbers and round to the least number of decimal places in any of the measurements used.

Deci

d=10^{-1}

Centi

c=10^{-2}

Mili

m=10^{-3}

Micro

µ=10^{-6} or mc

Nano

n=10^{-9}

Pico

p=10^{-12}

Femto

f=10^{-15}

Deka

da=10^{1}

Hecto

h=10^{2}

Kilo

k=10^{3}

Mega

M=10^{6}

Giga

G=10^{9}

Tetra

T=10^{12}

Peta

P=10^{15}

percent formula

(amount of a compartment/amount of whole)* 100%

Density

density=(mass/volume)

Specific gravity

(density of a substance/density of H2O)

Mass of an atom

Proton + Nutron

Atomic number

the number of protons in each atom

Average mass

(total mass/total numbers of atoms)

Rows

Each row (left to right) is called a period and as you go across the period elements become less metallic as well as decrease in size.

Colum

Each column (top to bottom) is called a group and as you go down a group the elements become more metallic as well as increase in size

1A

Alkali Metal

2A

Alkali earth metal

6A

Chalcogen

7A

Halogen

8A

Noble gases

Formula for shell count

2n^{2}

1

mono

2

Di

3

Tri

4

tetra

5

Penta

6

Hexa

7

hepto

8

octa

9

nona

10

deca

Cation

when an atom/molecule loses electrons and becomes positively charged. a cation usually shares a name with the atom it derived from

Anion

when an atom/molecule gains electrons and becomes negatively charged. an anion usually ends with -ide.

Group 1A

always loses 1 electron

Group 2A

always loses 2 electrons

Ag

loses 1 electron

Zn &Cd

always loses 2 electron

Al

always loses 3 electron

Group 5A

always gains 3 electrons (N & P only)

Group 6A

always gains 2 electrons (O, S, Se, only)

Group 7A

always gains 1 electron

Shape of a molecule

= (number of electron groups) + (number of bonding groups) + (number of lone pairs)

Number of electron groups

= (number of bonding groups) + (number of lone pairs)

Electronegativity

the ability of an atom to attract electrons and form covalent bonds. it became larger as you go across the periodic table and smaller as you go down a periodic table

Polar covalent bond

when the electron isn’t shared equally

Nonpolar covalent bond

when the electron is shared equally

Degree of bond polarity

En=I Ena - Enb I - the bigger the difference is the more poplar the covalent bond is.

metals under normal temperatures

Hg(l), M(s)

Noble gases under normal temperatures

G(g)

Diatomic non-metals under normal temperatures

I2(s), Br2(l)

other elements under normal temperatures

H2(g), P4(s), S8(s), X(s), Cl2(g)

Carbonate

Co3^{2-)

Bicarbonate

HCO^{3-}

Acetate

CH3COO^{-} or CH3CO2^{-} or C2H3O2^{-}

Cyanide

CN^{-}

Oxalate

C2O4^{2-}

Nitrite

NO2^{-}

Nitrate

NO3^{-}

Hydroxide

OH^{-}

Perioxide

O2^{2-}

Phosphate

PO4^{3-}

Hydrogen phosphate

HPO4^{2-}

Dihydrogen phosphate

H2PO4^{-}

Sulfite

SO3^{2-}

Hydrogen sulfite (Bisulfite)

HSO3^{-}

Sulfate

SO4^{2-}

Hydrogen sulfate (bisulfate)

HSO4^{-}

Thiosulfate

S2O3^{2-}

Chromate

CrO4^{2-}

Dichromate

Cr2O7^{2-}

Hypochlorite

ClO^{-}

Chlorite

ClO2^{-}

Chlorate

ClO3^{-}

Perchlorate

ClO4^{-}

Permanganate

MnO4^{-}

Polyatomic cation

ammonium (NH4^{+}) and Hydronium ion (H3O^{+})

Oxyanions (Oxyanions)

Polyatomic anions containing oxygen (except CN^{-}). Their names usually end with -ite or -ate