The Periodic Table

Group vs. Period Group- column Similar chemical and physical properties (react similarly) Period- row Number of shells

Let’s Label the Table

Groups ~ Families Alkali metals (1)- react with water to from an alkaline solution Alkali earth metals (2)- reactive, but not as reactive as Group 1 Transition metals (middle)- valence electrons are present in more than one shell

More Groups ~ Families Chalcogens (6)- found in copper ore Halogens (7)- are very reactive; only one electron to fill outer shell Noble gases (8)- almost non-reactive because have completely filled outer shells

Metals Usually solids at room temperature Properties: electrical conductors have luster malleable

Non-metals Elements in the upper right corner of the periodic table. Properties: generally brittle non-lustrous poor conductors of heat and electricity can be gases, brittle solids, liquid

Metalloids Elements that lie on a diagonal line between the metals and non-metals. Their chemical and physical properties are intermediate between the metals and non- metals

Periodic Table Trends

Atomic Radius Definition: measure of the size of atoms the distance from the nucleus to the edge of the electron cloud (shell)

Atomic Radius- Trends How does atomic radius change as you go down a group? –bigger (increases) Why?- more electrons How does atomic radius change as you go across a period? - smaller (decreases) Why?- radius contracts as charge increases Na Mg Al Si P S Cl Ar

Ionization Energy Definition: amount of energy required to completely remove an electron (from a gaseous atom) 1st ionization energy- energy required to remove 1st electron 2nd ionization energy – energy required to remove 2nd electron; greater than first 3rd ionization energy – energy required to remove 3rd electron; greater than first or second

Ionization Energy- Trends Li+1 Ca+1 K+1 Rb+1 Cs+1 How does ionization energy change as you go up a group? - increases Why?- electron is further away from the attraction of the nucleus How does ionization energy change as you go across a period? - increases Why?- nuclear charge is increasing

Electronegativity Definition: the tendency for an atom to attract electrons to itself when it is chemically combined with another element

Electronegativity- Trends How does electronegativity change as you go down a group? - decreases Why?- bonding pair of electrons moves farther away from nucleus-> more willing to share How does electronegativity change as you go across a period? - increases Why?- charge increases -> more attraction Non-metals want electrons (these are on the right side of the table)

Overview- Trends… Electronegativity Atomic Radius Ionization Energy Arrows show direction of increasing Atomic Radius Ionization Energy

Practice~ Atomic Radius Circle the atom that has the LARGER atomic radius Li or O K or Na

Practice~ Ionization Energy Circle the particle in each pairs has the LOWER ionization energy Al or B Mg or Na

Practice~ Electronegativity Circle the atom in each pair with the HIGHER electronegativity. O or S Li or F