Chapter 4:The Perodic Table Flashcards
Triad
is a group of three element with similar properties where the atomic weight of the middle element is approxiamately equal to the average of the other two.
element
is a substance that cannot be split into simpilar substances by chemical means.
Newland’s Octaves
are arrangements of elements in which the first and the eighth element.counting from a particular event ,have similar properties
Mendeleev’s Periodic Law
When elements are arranged in order of increasing atomic weight,the properties of the elements reoccur periodically
Atomic number
of an atom is the number of protons in the nucleus of that atom
Modern Periodic Table
Is an arrangement of elements in order of increasing atomic number
Mass Number
of an element is the sum of the number of protons and neutrons in the nucleus of an atom of that elements
Isotopes
Are atoms of the same element which have different mass numbers due to the different number of neutrons in the nucleus
Relative Atomic Mass
The average of the mass numbers of the isotopes of the element
As they occur naturally
Taking their abundance into account and
Expressed on a scale in which the atoms of the carbon isotope have a mass of exactly 12 units
Principle of Mass Spectromerty
Is that changed particles moving in a magnetic field are deflected to different extents according to their masses and are thus separated to these masses
Eletron Configuration
Shows the arrangement of electrons in an atom of an element
Aufbau Principle
When building up the electron configuration of an atom in its ground state,the electrons occupy the lowest available energy levels
Hund’s Rule of Maximum Multiplicity
States that when two or more orbitals of equal energy are available,the electrons occupy them singly before filling them in pairs
Pauli Exclusion Principle
State that no more than two electrons may occupy an orbital and they must have opposite spin
Greek philosophers suggested that all substances were made up of four elements.What were they?
Fire
Earth
Water
Air
