need to know - atomic theory

c = λν

c=

speed of light

c = λν

λ (lambda) =

wavelength

c = λν

v =

frequency

c =

3.00 × 10⁸ m/s

E=hν

E=

energy

E=hν

h=

planck’s constant

E=hν

h= (numerically)

6.626×10^−34 Js

E=hν

v=

frequency (Hz)

a chemical compound always contains the same elements in exactly the same proportions BY MASS

law of definite proportions

law of conservation of mass

mass cannot be created or destroyed in pedantry chemical and physical changes.

therefore, the mass of the reactants is equal to the mass of the products.

when two elements combine to form two or more compounds, the mass of one element that combines with a given mass of the other is in the ratio of small whole numbers.

law of multiple proportions

Daltons atomic theory

All matter is composed of extremely small particles called atoms, which cannot be subdivided, created, or destroyed

dalton’s atomic theory

Atoms of a given element are identical in their physical and chemical properties

dAltons atomic theory

Atoms of different elements differ in their physical and chemical properties

daLtons atomic theory

Atoms of different elements combine in simple, whole-number ratios to form compounds

dalTos atomic theory

In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed

aufbau’s principle

electrons will occupy orbitals from lowest to highest energy

hund’s rule

when there are multiple orbitals of equal energy, place one electron in each before pairing them up

pauli exclusion principal

No more than two electrons can occupy any single s, p, d, or f orbital.