Chapter 6 The Periodic Table 6.3 Periodic Trends 6.1 Organizing the Elements 6.2 Classifying the Elements 6.3 Periodic Trends Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Trends in Ionization Energy Atomic Radius – one-half the distance between the nuclei of two atoms of the same element when the atoms are joined. Ionization Energy – energy required to remove one electron from an atom. Electronegativity – ability of an atom of an element to attract electrons when the atom is in a compound. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Trends in Atomic Size Atomic Radius: one-half the distance between the nuclei of two atoms of the same element when the atoms are joined. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Trends in atomic size. Trends in Atomic Size Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Trends in Atomic Size In general, atomic size increases from top to bottom within a group, and decreases from left to right across a period. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Which atom in each pair has the larger atomic radius? Li or K Ca or Ni CHEMISTRY & YOU Which atom in each pair has the larger atomic radius? Li or K Ca or Ni Ga or B O or C Cl or Br f) Be or Ba Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Ions An atom or group of atoms that has a positive or negative charge. Atoms become ions when electrons are lost or gained. Atoms can become cations or anions Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Cation – ion with a positive charge Ions Cation – ion with a positive charge Metals form cations. Smaller than the atoms they form from Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Anion – ion with a negative charge Ions Anion – ion with a negative charge Nonmetals form anions. Larger than the atom they form from Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Group Trends in Ionic Size Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

The figure below summarizes the group and period trends in ionic size. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Trends in Ionization Energy Ionization Energy – energy required to remove one electron from an atom. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Ionization Energies of Some Common Elements Interpret Data Ionization Energies of Some Common Elements Symbol First Second Third H 1312 He (noble gas) 2372 5247 Li 520 7297 11,810 Be 899 1757 14,840 C 1086 2352 4619 O 1314 3391 5301 F 1681 3375 6045 Ne (noble gas) 2080 3963 6276 Na 496 4565 6912 Mg 738 1450 7732 S 999 2260 3380 Ar (noble gas 1520 2665 3947 K 419 3096 4600 Ca 590 1146 4941 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Electronegativity Values for Selected Elements Interpret Data Electronegativity – ability of an atom of an element to attract electrons when the atom is in a compound. Electronegativity Values for Selected Elements H 2.1 Li 1.0 Be 1.5 B 2.0 C 2.5 N 3.0 O 3.5 F 4.0 Na 0.9 Mg 1.2 Al Si 1.8 P S Cl K 0.8 Ca Ga 1.6 Ge As Se 2.4 Br 2.8 Rb Sr In 1.7 Sn Sb 1.9 Te I Cs 0.7 Ba Tl Pb Bi Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Trends in Electronegativity In general, electronegativity values decrease from top to bottom within a group. For representative elements, the values tend to increase from left to right across a period. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Trends in Electronegativity Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

CHEMISTRY & YOU Arrange the following groups of elements in order of increasing ionization energy. Be, Mg, Sr → Sr, Mg, Be Bi, Cs, Ba → Cs, Ba, Bi Na, Al, S → Na, Al, S Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

1. Which has the smallest ionization energy; Trends in Atomic Size Practice Problems 1. Which has the smallest ionization energy; Sodium, Calcium, Potassium, Magnesium 2. List in order of increasing ionization energy (smallest to largest) Beryllium, Cesium, Oxygen, Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Which element in each pair has a higher electronegativity value? CHEMISTRY & YOU Which element in each pair has a higher electronegativity value? Cl or F C or N Mg or Ne As or Ca Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

CHEMISTRY & YOU When the elements in each pair are chemically combined, which has a greater attraction for electrons? Ca or O O or F H or O K or S Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Which element in each pair has the larger atomic radius? Na or Li CHEMISTRY & YOU Which element in each pair has the larger atomic radius? Na or Li Sr or Mg C or Ge Se or O Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Which particle has the larger radius in each atom/ion pair? CHEMISTRY & YOU Which particle has the larger radius in each atom/ion pair? Na, Na+ S, S2- I, I- Al, Al3+ Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

Which element in each pair has a greater first ionization energy? CHEMISTRY & YOU Which element in each pair has a greater first ionization energy? Li or B Mg or Sr Cs or Al Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .