ATOMS AND PERIODIC TABLE Flashcards
a positive charge particles
Proton
no charge associated with it
Neutron
negative electrical charge, smallest in terms of mass
Electrons
found at the center of an atom
all protons and all neutrons
the outer region of an atom contains
all the electrons
a subatomic particle found in the nucleus of an atom
Nucleon
placed as a superscript; above
Mass number
placed as a subscript; below
Atomic number
A= number of protons + number of neutrons
Mass number
z = number of protons = number electrons
Atomic number
determined by the numbers and arrangement of electrons about the nucleus
Chemical Properties of an atom
pure substance in which all atoms present have the same atomic number
Element
atoms of an element that have the same of protons and the same number of electrons but different numbers of neutrons
Isotopes
calculated average mass for the isotopes of an element, expressed on a scale where 12/6 C serves as the reference point
Atomic Mass
states that when elements are arranged in increasing atomic number, elements with similar chemical properties occur in periodic (regularly recurring) intervals
Periodic Law
A tabular arrangement of the elements in order of increasing atomic number such that elements having similar chemical properties are positioned in vertical columns
Periodic Table
a horizontal row
Period
a vertical column
Group
An element that has the characteristic properties of luster, thermal conductivity, electrical conductivity, and malleability
Metal
an element characterized by the absence of properties of luster, thermal conductivity, electrical conductivity and malleability
Nonmetal
the majority of the elements are
Metal
- Approximately 93 elements are metals, depending on how the artificially synthesized elements are classified. Only about 18 of the elements are classified as nonmetals.
restricted to specific regions within the extranuclear portion of the atom
Electrons
limited to certain values, and a specific behavior is associated with each allowed energy value
Electron Energies
the space in which electrons move rapidly about is divided into subspaces called (3)
Shells
Subshells
Orbitals
he developed theory about atom which is known as dalton’s atomic theory
John Dalton (1803) in my notes (1802)
a region of space about a nucleus that contains electrons that gave approximate the same energy and that spend most of their approximately the same distance from the nucleus
Electron Shell
Electron shells are numbered by
1, 2 ,3 and so on, outwards from the nucleus
a region of space within an electron shell that contains electrons that have the same energy
Electron subshell
the number of subshell within a shell is the same as the
shell number
differ in size, and each type is designated using the letters s,p,d and f
Subshells
subshell with 2 electrons
s subshell
subshells with 6 electrons
p subshell
subshell with 10 electrons
d subshell
subshell with 14 electrons
f subshell
used in identifying subshells
Both number and a letter
gives the shell within which the subshell is located
Number
gives the type of subshell
Letter
a region of space within an electron subshell where an electron with a specific energy
Electron Orbital
can accommodate maximum of 2 electrons
Electron Orbitals
( 2 electrons) contains one orbital
s subshell
(6 electrons) contains three orbitals
p subshell
(10 electrons) contains five orbitals
d subshell
(14 orbitals) contains seven orbitals
f subshell
orbitals: spherical in shape
S orbital
orbitals: have shaped similar to to the figure 8
p orbitals
orbitals: a clover shape
d orbital
orbitals: no definite shape
f orbital
Electron subshells are filled in order of
increasing energy
however, energies of subshells in different shelf
overlap
the 4s subshell has lower energy that the
3d subshell
dictates the manner in which electrons are filled in the atomic orbitals of an atom in its ground state.
Aufbau Principle or Aufbau Rule
a statement of how many electrons an atom has in each of its electron subshells
Electron Configuration
superscipt following each subshell designation indicated the
number of electrons in that subshell
written in symbols; using number-letter combination
Electron Configuration
groups (columns) of elements have similar chemical properties because similarities in their what
electron configuration
how many orbitals are there in s subshell
1 orbital
how many orbitals are there in p subshell
3 orbitals
how many orbitals are there in d subshell
5 orbitals
how many orbitals are there in f subshell
7 orbitals
