Ion charges and general vocab

Ag

+1

Zn

+1

Cd

+2

Al

+3

Group 1 (Alkali Metals)

$$+1$$

Group 2 (Alkaline Earth Metals)

$$+2$$

Group 13 elements

$$+3$$

Group 15 elements

$$-3$$

Group 16 elements

$$-2$$

Group 17 (Halogens)

$$-1$$

N

-3

P

-3

amu=

((%/100) x isotope mass 1) + ((%/100) x isotope mass 2)…

number at the top of element box

atomic number

atomic number =

number of electrons and number of protons

number at bottom of element square

average atomic mass

neutrons =

mass - atomic number

A = mass

Z = atomic number

X = atomic symbol

when atom is neutral,

protons = electrons

cm³=

mL

Law of Multiple Proportions

two elements form a series of compounds, the rations of the masses of the elements can be reduced to small whole numbers, the compared compounds must have the same elements

Law of conservation of mass

mass is neither created nor destroyed in a chemical reaction, mass of reactants = mass of products

mixture

two or more pure substances

homogenous mixture

macroscopically uniform, ex. salt water

heterogenous mixture

macroscopically different, ex. sand water

filtration

separation used to remove undissolved solid from solution

distillation

depends on the boiling points of the two liquids in a mixture to separate them, ex. water and ethanol, ethanol has a lower boiling point

density =

mass/volume

intensive property

characteristic that does NOT depend on the amount of matter, ex. density

extensive property

characteristic that DOES depend on the amount of matter present, ex. mass, volume

pure substance

form of matter that cannot be separated

law of conservation of energy

energy cannot be created nor destroyed, can be transferred, total energy of the universal is constant

compound

multiple elements with a fixed ratio, can be chemically decomposed

law of definite proportion

given compound always contains same proportion of elements by mass

energy

capacity to do work/produce heat

potential energy

energy results from objects postion, ex. object held up in air has gravitational potential energy, entended spring, separation of electrons, fuel is chemical potential energy, charge is electrostatic potential energy, can be interconverted with kinetic energy (law of conserv. of energy)

kinetic energy

energy associated with motion, ex. particles have thermal energy, macroscopic items have mechanical energy, electrons in conductors have electrical energy, space between molecules that allow sound to pass through have acoustic energy, can be interconverted with potential energy (law of conserv. of energy)

accuracy

how close a measurement is to the actual value, take average

precision

how close measurements are to each other

random errors

produce varitaion between repeated measurements and tend to average out with more measurements taken, affects accuracy

K=

C + 273.15

F=

(C x 9/5) + 32

big difference between compounds and mixtures

compound: different characteristics, definite proportions

mixture: similar characteristics, indefinite proportions

both: consist of 2+ elements

water’s rare property

solid form is less dense than liquid form

sig fig rule for logs

the result will have the same number of decimals as there are in sig figs in the log

sig fig rule antilogs/exponent

the result will have the same number of sig figs as there are decimals in the exponent

dalton

1. each element is made of atoms

2. the atoms of 1 element are identical, the atoms between elements are different

3. atoms of different elements combine to form chemical compounds

4. chemical reactions involve reorganization of the atoms; only changes the way they are bound to each other, not the atom itself

thomson

1. cathode rays: passing a beam through electric and magnetic fields

2. the beam deflected towards the positive plate; cathode rays consist of electrons

3. electron’s charge-to-mass ratio (e/m): -1.76 × 10^8 c/g

4. electrons present in all atoms

5. atoms are electrically neutral, so must also contain positive charge

6. plum pudding model: electrons embedded randomly in positive cloud

millikan

1. suspended oil droplets between two electrically charged plates

2. electric field balanced droplet, calculate charge of electron: -1.60 × 10^-19 C

3. Millikan’s charge and thomas’ charge-to-mass ration led to electron mass: -9.11 × 10^-31 kg

rutherford

1. directed positively charged a particles at thin gold foil

2. positive charge should not encounter concentrated negative particle to repel it if it is evenly spread

3. many positive particles; others deflected at large random angles

4. explanation: most of the atom is empty space with a dense, positively charged center— nucleus

group 1

akali metals

group 2

alkaline earth metals

group 17

halogens

CH4

Methane

C2H6

ethane

C3H8

propane

C4H10

butane

NH3

ammonia

N2H4

hydrazine

PH3

phosphine

NO

nitric oxide

N2O

nitrous oxide (laughing gas)

H20

water