periodic table definitions Flashcards
(11 cards)
atomic radius of an atom
the atomic radius of an atom is defined as half the distance between the nuclei of two of the same elements joined together by a single covalent bond
first ionisation energy of an atom
the first ionisation energy of an atom is the energy required to completely remove the most loosely bound electron from a neutral gaseous atom
2nd ionisation energy of an atom
the 2nd ionisation energy of an atom is the energy required to completely remove the 2nd most loosely bound electron from a positive ion
electronegativity
electronegativity is the relative attraction an atom in a molecule has for the shared pair of electrons in a covalent bond
periodic table
periodic table is a table which contains the known elements
element
an element is a substance that cannot be broken down into anything simpler by chemical means
dobereiner’s triad
dobereiner’s traid is defined as a group of three elements with similar chemical properties in which the atomic weight of the middle element is approximately equal to the average of the other two
newland’s law of octaves
newland’s law of octaves is when the elements are arranged in order of increasing atomic weight, the first and eighth element have similar properties
mendeleev’s periodic law
mendeleev’s periodic law states that if the elements are arranged in order of increasing atomic weight, the elements will vary their properties periodically
isotopes
isotopes are atoms with the same atomic number but different atomic mass number due to the number of neutrons in the nucleus
relative atomic mass
relative atomic mass is defined as 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-12 isotope has a mass of exactly 12 units
