Periodic Table: Patterns

Mendeleev’s Predictions

Property Ekasilicon Germanium

atomic mass 72 72.61

density (g/cm³) 5.5 5.35

melting point (°C) high 947

color grey grey

oxide density (g/cm³) 4.7 4.7

chloride boiling point under 100 °C 86 °C (GeCl4)

chloride density (g/cm³) 1.9 1.9

Mendeleev’s Prediction

Property Ekaaluminium Gallium

atomic mass 68 69.72

density (g/cm³) 6.0 5.904

melting point (°C) Low 29.78

oxide's formulaEa2O3 (density: 5.5 g/cm³) (soluble in both alkalis and acids)

Ga2O3 (density: 5.88 g/cm³) (soluble in both alkalis and acids)

chloride's formula Ea2Cl6 (volatile) Ga2Cl6 (volatile)

Periodic Law

• Elements are arranged by atomic number, there is a periodic repetition in their physical and chemical properties.

Periodic Table

• Horizontal rows: – Called “periods”– 7 periods

• Show the number of the shell

Periodic Table

• Vertical columns: – Called “groups”– Show the valance electrons– Elements in a group have similar physical and

chemical properties

Do Now

• Write the noble gas configuration and dot diagram for the following elements by only using the periodic table

• Nitrogen• Potassium• Manganese• Iodine• Germanium

Periodic Table with f-block in place

Element Characteristics• Atomic radius

– Half the distance between the nuclei of two atoms. (Atoms are the same and bonded together)

Radius size

increases

Radius size increases

Element Characteristics• Ionization energy

– Energy required to remove an electron from an atom • Easier to remove an electron from group 1 than

group 8• Easier to remove electrons that are farther away

from the nucleus (elements at the bottom of a group)

Ionization energy increases

Ionization energy

generally increases

Element Characteristics• Electronegativity

– It is a measure of the element's ability to attract the electrons which are in a bond

Electronegativity increases

Electronegativity increases

Element Characteristics

Liquids

Solids More metallic

More nonmetallic Periodic

Table

Periodic Table Trends: Summary

Atomic radius decreases

Ionization energy and

Electronegativ

ity increase