Chemistry 4.1, 4.2, 4.3 and 5

what was the major shortcoming of Rutherford’s model of an atom?

what was the major shortcoming of Rutherford’s model of an atom?

His model didn’t explain how the electrons were distributed through the space surrounding the nucleus and didn’t explain why the negatively charged electrons were not attracted to the positive nucleus.

frequency and wavelength equation

3.00×10^8 = wavelength times frequency

quantum of energy equation

Energy = 6.626×10^-34x frequency

electromagnetic radiation

a form of energy that exhibits wavelike behavior as it travels through space

wavelength

the distance between corresponding points on adjacent waves

frequency

the number of waves that pass a given point in time.

quantum

the minimum amount of energy that can be lost or gained by an atom

photon

a particle of electromagnetic radiation having zero mass and carrying a quantum of energy

quantum theory

describes mathematically the wave properties of electrons and other very small particles

orbital

an orbital is a 3 dimensional region around the nucleus that indicates the probable location of an electron

quantum numbers

specify the properties of atomic orbitals and the properties of electrons in orbitals

principle quantum number

symbolized by n, indicates the main energy level occupied by the electron

n squared

total number of orbitals in a given shell

angular momentum quantum number

symbolized by L indicates the shape of the orbital.

s orbital

sphere

p orbital

dumbell shape

d orbital

varies

f orbital

varies

magnetic quantum number

symbolized by m indicates the orientation of an orbital around the nucleus

spin quantum number

only has 2 values -1/2 or +1/2. this indicates the 2 fundamental spin states of an electron in an orbital

electron configuration

the arrangement of electrons in an atom

aufbau principle

an electron occupies the lowest energy orbital that can receive it

pauli exclusion principle

no two electrons in the same atom can have the same set of 4 quantum numbers

hunds rule

orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin state

periodic law

the physical and chemical properties of the elements are periodic functions of their atomic numbers

periodic table

an arrangement of elements in order of their atomic numbers so that elements with similar properties fall in the same column or group

mendeleev

made periodic table in order of atomic mass and properties of elements

moseley

arranged periodic elements based on their atomic numbers

sir william ramsay

discovered noble gases

d block elements

groups 3-12. metals with typical metallic properties. good conductors of electricity and have a high luster. less reactive than group 1 and 2.

p block

groups 13-18. p block and s block are main group elements.

halogens

group 17

atomic radius

may be defined as one half the distance between 2 identical nuclei bonded together.

ion

an ion is an atom or group of bonded atoms that has a positive or negative charge

ionization

any process that results in the formation of an ion

ionization energy

the energy required to remove one electron from a neutral atom of an element

cation

a positive ion

anion

negative ion

electronegativity

a measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound.