Term | Definition |
Energy Level | An energy level is defined as the fixed energy value that an elecron in a atom may have |
An Orbital | An orbital is an region in space within which there is a high probability of finding an electon |
An Element | An Element is a substance that cannot be split up into simpler substances by chemical means |
A Triad | A triad is a group of 3 elements with similar chemical properties in which the atomic weight of the middle element is approximately equal to the average of the other two |
Newlands Octaves | Newlands Octaves are groups of elements arranged in order of increasing atomic weight within which the first and eight element of each group have similar chemical properties |
Mendeleev's Periodic Law | Mendeleev's Periodic Law states that when elements are arranged in order of increasing atomic weigh the properties of the elements vary periodically |
Atomic Number | Atomic Number of an atom is the number of protons in the nucleus of that atom |
Modern Periodic Table | Modern Periodic Table is an arrangement of the elements in order of increasing atomic number |
When Elements Are Arranged ... | When Elements Are Arranged in order of increasing atomic number the properties of the elements vary periodically |
Mass Number | Mass Number of an element refers to the number of protons and neutrons in the nucleus of an atom of that element |
Isotopes | Isotopes are atoms of the same element (i.e. they have the same atomic number)that have different mass numbers due to a different number of neutrons in the nucleus |
Relative Atomic Mass | Relative Atomic Mass is defined by:
-The avarage of the mass number of the isotopes of that element
-as they occur naturally
-taking their abundances into account
-Expressed on a scale in which the atoms of the Carbon 12 isotope have a mass of exactly |
Aufbau Principal | Aufbau Principal states that when building up electronic configuration of an atom is its ground state,the electrons occupy the lowest available energy level |
Hund's Rule of Maximum Multiplicity | 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 |
The Pauli Exclusion Project | The Pauli Exclusion Project states that no more than 2 electrons can occupy an orbital and they must have opposite spin |