Chem unit 4 Flashcards
Part 1
First person to arrange the element by similar properties in increasing atomic mass
John newlands
Who published the periodic table in 1869
lothar Meyer
Who arranged to the elements by the atomic number
Henry Mosely
Who published the periodic table in 1870 leaving gaps for undiscovered elements and arrange them by weight
Dimitri mendeleev
Elements properties and function functions of their atomic number
Periodic law
To the left of the staircase, mostly solid at temperature except mercury
Metals
Group =
Column
Periods =
Rows
Right of staircase, liquids, and gases at room temp
Nonmetals
Two sides, touching staircase, except aluminum
Metalloids/semi conductors
S&P Block
Main group elements
Group Except h, very reactive with water, one valence electron, soft and shiny, lower boiling point and melting point that most metals
Alkali metals
, two valence electrons, harder and more dense, higher melting point in boiling point, dull in color
Alkali earth metals
D&F block, wide range of properties
Transition metals
4F row
Lathanides
5F row
Actinides
Transition metals, Actinides and lathanides are
All radioactive
very reactive with metals Which form salts (Any ionic compound that doesn’t contain h+ or OH-)
Halogens
very unreactive, full octet stable
Noble gases
Group of its own
Hydrogen
Patterns of properties of elements
Periodic trend
Tendency of an atom to attract electrons
Electronegativity
Electronegativities trend
Increases right and up
Reasons for electronegativities trend. L-R
More protons and nucleus equals greater effective nuclear charge, greater attraction for electrons
Reasons for electronegativities trend going up
Valence electrons get closer to the nucleus and there’s less electron shielding equals stronger pool on electrons
Core electrons shield, valence electrons
Electron shielding
Energy required to remove electrons
Ionization energy
Trend for ionization energy
Increases Right and up
Reasons for ionization trend left to right
same an EN, more protons greater effective nuclear charge = greater pool on electrons = more energy to remove electrons
Reasons for ionization energy bottom up
same as EN, Valence electrons are closer to nucleus and less shielding means greater on electrons and more energy to remove electrons
Half the distance between center of two nuclei
Atomic radius
Trend for atomic radius
Increases Down and left
Reason for trend in atomic radius right to left
Who were protons less effective nuclear charge? E/E repulsion increases meaning bigger atoms.
Reasons for atomic radius trend to increase going down
Valance electrons get farther from nucleus and move electrons shielding
Cations in atomic radius
Decrease e/e repulsion and radius decreases
Anions in atomic radius
Increases e/e repulsion and radius increases
Energy given off when an electron is added
Electron affinity
Trend for electron affinity
Gets more negative to the right and up
Reasons for electron affinity
Gives off energy equals more stable
Most metallic elements are lower on the periodic table
Metallic character
