periodicity

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3.1 periodic tables:

understanding:

the periodic table is arranged into 4 blocks, s, p, d and f

the periodic table is arranged in to groups. group: vertical column of elements, increasing number of inner shells, the same amount of outer shells.

the periodic table is arranged into periods: period: horizontal column of elements, same number of shells, increasing number of electrons in the outer shell

group number: no. of valence electrons

period number: no. of electron shells

The number of the principal energy level and the number of the valence electrons in an atom can be deduced from its position on the periodic table.

lanthanoides and actinoids both make up the f blocks. L^ A v

metalloids are physically similar to metals but chemically similar to non-metals

applications and skills:

deduction of electron configuration in atom, based on position in periodic table

first ionization energy - the first ionization energy is the minimum energy required to remove a mole of electrons from a mole of gaseous ions to form a mole of univalent cations in the gaseous state. It is the enthalpy change for the reaction:

X(g) -> X+(g) + e-

electronegativity - electronegativity is a measure of the tendency of an atom in a molecule to attract a shared pair of electrons to itself.