S-113

• What is the periodic Table?• How is it arranged?

S-116

• What subatomic structure is reflected in the periodic table?

SPS4 Students will investigate the arrangement of the Periodic Tablea. Determine the trends of the following

Number of valence electronsTypes of ions formed by representative elementsLocation of metals, nonmetals, and metalloidsPhases at room temperature

b. Use the Periodic Table to predict the above properties for representative elements

Unit 5 The Periodic Table

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

• 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 ElementsHow did Mendeleev organize the elements in his periodic 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

5.1 Organizing the ElementsWhat evidence helped verify the usefulness of Mendeleev’s table?

S-118

• What two characteristics are used to organize 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

• 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 TableHow 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 TableHow is the modern periodic table organized?

• 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 TableWhat does the atomic mass of an element depend on?

• Elements are classified in three ways– Natural vs Man made

• Technetium (Tc)• All elements above 92

5.2 The Modern Periodic TableWhat 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 TableWhat 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 TableWhat categories are used to classify elements on 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

5.2 The Modern Periodic TableHow do properties vary across a period in the periodic table?

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?

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

• 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 GroupsWhy do the elements in a group have similar properties?

• Alkali Metals – Group one– 1 valence electron– React by losing 1 electron– Gain a positive charge– Highly reactive

5.3 Representative GroupsWhat 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 GroupsWhat 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 GroupsWhat are some properties of the A groups?

• Carbon Family – Group 14– 4 valence electrons– React by sharing electrons

5.3 Representative GroupsWhat are some properties of the A groups?

• Nitrogen Family– Group 15– 5 valence electrons– React by gaining electrons– Gain negative charge

5.3 Representative GroupsWhat 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 GroupsWhat 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 GroupsWhat are some properties of the A groups?

• Noble Gases – Group 18– 8 valence electrons– Do not react or form compounds

5.3 Representative GroupsWhat 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 GroupsWhat 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

5.3 Representative GroupsWhat are some properties of the A groups?