Gen Chem 1 Exam 1

mega (M)

10⁶

kilo (k)

10³

deci (d)

10^-1

centi (c

10^-2

milli (m)

10^-3

micro (u)

10^-6

nano (n)

10^-9

pico (p)

10^-12

Law of Conservation of Mass

in a chemical reaction, matter is neither created nor destroyed (total mass of used reactants = total mass of products)

Law of definite proportions

any given compound is composed of the same definite proportions by mass of its elements

Law of multiple proportions

an element may combine in different ratios (different proportions) with another element to form different compounds

Daltons atomic theory of matter (1)

matter is made up of very tiny indivisible particles called atoms

Dalton’s atomic theory of matter (2)

Each atom of a particular element has an identical mass, but the mass of an atom of one element is different from the mass of an atom of any other element

Daltons atomic theory of matter (3)

Atoms combine in whole number ratios to form what we now call molecules

Daltons atomic theory of matter

atoms of some pairs of elements can combine with each other in different small whole-number ratios to form different compounds

Which dalton’s atomic theories have been disproven

1 & 2

J. J. Thomson (1897)

saw that mass to charge ratio of the particles was the same no matter what cathode material he used, these electrons were fundamental particles found in all matter

Robert Millikan

determined the charge of an electron, used Thomson’s mass-to-charge

Thomson’s plum-pudding model

atom is composed of positive cloud of matter in which electrons are embedded

Ernest Rutherford

observed alpha and beta particles could be deflected by magnetic fields

Gold foil experiment (Rutherford gold foil experiment)

led to discovery of the atoms nucleus