S-113 What is the periodic Table? How is it arranged?

S-116 What subatomic structure is reflected in the periodic table?

Unit 5 The Periodic Table SPS4 Students will investigate the arrangement of the Periodic Table a. Determine the trends of the following Number of valence electrons Types of ions formed by representative elements Location of metals, nonmetals, and metalloids Phases at room temperature b. Use the Periodic Table to predict the above properties for representative elements

5.1 Organizing the Elements How did Mendeleev organize the elements in his periodic table? What evidence helped verify the usefulness of Mendeleev’s table?

5.1 Organizing the Elements How did Mendeleev organize the elements in his periodic table? 1860 Mendeleev organizes the periodic table Rows (called periods) by increasing mass Later by atomic number Columns (called groups or families) by similar chemical and physical properties Periodic – means that properties repeat at regular intervals Only knew 63 elements He predicted the properties of blanks in his periodic table

5.1 Organizing the Elements What evidence helped verify the usefulness of Mendeleev’s table? Mendeleev predicted elements Eka-aluminum (one below aluminum) Soft metal with a low melting point and a density of 5.9 g/cm3 1875 Gallium (Ga) discovered Soft metal, melting point 29.7oC, density of 5.91 g/cm3 Proved the patterns could be used to predict elements

S-118 What two characteristics are used to organize the modern periodic table?

5.2 The Modern Periodic Table How is the modern periodic table organized? What does the atomic mass of an element depend on? What categories are used to classify elements on the periodic table? How do properties vary across a period in the periodic table?

5.2 The Modern Periodic Table How is the modern periodic table organized? Periodic Law Elements are arranged in order of increasing atomic number (protons) Period – rows on the periodic table As the row number increases outside electrons are in higher energy levels First energy level hold 2 – so hydrogen and helium have electrons in first energy level Second energy level holds 8 – so second row has eight elements

5.2 The Modern Periodic Table How is the modern periodic table organized? Periodic Law Properties of elements repeat in predictable ways and are used to place element in columns Group – columns Numbered 1-18 Some have names 1 alkali metals 2 alkaline earth metals 17 halogens 18 noble gases

5.2 The Modern Periodic Table What does the atomic mass of an element depend on? Atomic Mass Measured in atomic mass units (u) One twelfth of the mass of Carbon-12 Average Atomic Mass - calculated using weighted averages The abundance of an isotope (add up to 100%) Mass of each different isotope

5.2 The Modern Periodic Table What categories are used to classify elements on the periodic table? Elements are classified in three ways Natural vs Man made Technetium (Tc) All elements above 92

5.2 The Modern Periodic Table What categories are used to classify elements on the periodic table? Elements are classified in three ways State of Matter at room temperature Liquids – Hg, and Br Gases – Group 18, H, N, O, F, Cl Solids – the rest of the elements up to 92

5.2 The Modern Periodic Table What categories are used to classify elements on the periodic table? Elements are classified in three ways Metals, Non-Metals, Metalloids Metals Left of zig-zag line Transition Metals – group 3-12 Non-Metals – right of zig-zag line Metalloids – touch the zig-zag line, except Aluminum

5.2 The Modern Periodic Table How do properties vary across a period in the periodic table? Changes in properties across a periodic table From left to right Become less metallic, more nometallic More likely to gains electrons, less likely to lose them

S-119 For the element Iron, answer the following questions 1. metal, nonmetal, metalloid? 2. state of matter at room temperature? 3. average atomic mass? 4. name of group? 5. period?

5.3 Representative Groups Why do the elements in a group have similar properties? What are some properties of the A groups in the periodic table?

5.3 Representative Groups Why do the elements in a group have similar properties? Valence Electrons Electrons in the highest occupied energy level Major factor in chemical reactions Elements in the same group, have the same valence electrons

5.3 Representative Groups What are some properties of the A groups? Alkali Metals Group one 1 valence electron React by losing 1 electron Gain a positive charge Highly reactive

5.3 Representative Groups What are some properties of the A groups? Alkaline Earth Metals Group two 2 valence electrons React by losing 2 electron Gain a positive charge Less reactive

5.3 Representative Groups What are some properties of the A groups? Boron Family Group 13 3 valence electrons React by losing 3 electron Gain a positive charge

5.3 Representative Groups What are some properties of the A groups? Carbon Family Group 14 4 valence electrons React by sharing electrons

5.3 Representative Groups What are some properties of the A groups? Nitrogen Family Group 15 5 valence electrons React by gaining electrons Gain negative charge

5.3 Representative Groups What are some properties of the A groups? Chalcogens (Oxygen Family) Group 16 6 valence electrons React by gaining electrons Gain negative charge More reactive

5.3 Representative Groups What are some properties of the A groups? Halogens Group 17 7 valence electrons React by gaining electrons Gain negative charge Very reactive

5.3 Representative Groups What are some properties of the A groups? Noble Gases Group 18 8 valence electrons Do not react or form compounds

5.3 Representative Groups What are some properties of the A groups? Transition Metals (Transition Elements) Group 3-12 2 valence electrons Additional electrons are filling lower energy levels All have similar properties What we think of as “Metals”

5.3 Representative Groups What are some properties of the A groups? Actinide and Lanthenide Series No group number 2 valence electrons Additional electrons are filling lower energy levels Very few things that we deal with on a regular basis

S-120 For the following elements list the number of valence electrons, and write the predicted ion. Nitrogen Beryllium Gold

S-121 For the element Antimony list Average atomic mass Atomic mass if the number of neutrons is 70 Number of valence electrons Charge on the ion