Unit 2: Atomic Structure and the Periodic Table Periodic Table Trends

The Periodic Table group: columns period: rows

Metals and Nonmetals Metals Nonmetals

Groups of the Periodic Table Alkali metals Noble gases Alkaline earth metals (Group 2 Metals) Halogens Transition Metals

Atomic Radius Atomic radius: the size of an atom

DECREASES due to fewer electron energy levels Atomic Radius DECREASES due to more protons (increased effective nuclear charge) DECREASES due to fewer electron energy levels

Ionization Energy Ionization energy: The energy required to remove the outermost (highest energy) electron from a neutral atom in its ground state.

Ionization Energy INCREASES – smaller atom means electrons are closer to the nucleus, thus harder to remove INCREASES – electrons are closer to the nucleus and there is less shielding

Electronegativity Electronegativity: ability of an atom in a molecule (covalent bond) to attract electrons

INCREASES – due to more protons (increased effective nuclear charge) Electronegativity INCREASES – due to more protons (increased effective nuclear charge) INCREASES – due to fewer electron energy levels (increased effective nuclear charge)

Periodic Table Trends Assignment ATOMIC RADIUS read p. 259-262 do p. 288: 7.4, 7.23 IONIZATION ENERGY read p. 264-268 do p. 290: 7.41 (skip a), 7.43, 7.45 ELECTRONEGATIVITY read p. 308 do p. 334: 8.36, 8.37