SPM Form 4: Periodic Table of elements (Checklist)

• Periodic Table: the table showing the elements in order of increasing proton number; similar elements are arranged in columns called groups.
• Group: A vertical column of elements in the Periodic table.
• Period: A horizontal row of the Periodic Table; its number tells you how many electron shells there are.
• Alkali metals: the Group I elements of the Periodic Table, which include lithium, sodium, potassium, rubidium, caesium and francium.
• Alkaline earth metals: the Group II elements of the Periodic Table, which include beryllium, magnesium, calcium, strontium, barium, and radium.
• Halogens: the Group VII elements of the Periodic Table, which include fluorine, chlorine, bromine, iodine and astatine.
• Noble gases: the Group 18 elements of the Periodic Table; they are called ‘noble’ or inert gases because they are so unreactive, which include helium, neon, argon, krypton, xenon and radon.
• Transition elements: the elements in the wide middle block of the Periodic Table (elements in group 3 to group 12).
• Metal: an element that shows metallic properties (for example conducts electricity, and forms positive ions)
• Non-metal - an element that does not show metallic properties: the non-metals lie to the right of the zig-zag line in the Periodic Table.
• Amphoteric oxide: An oxide that exhibits both acidic and basic properties.
• The atomic radius is a term used to describe the size of the atom.
• The ionization energy is the energy required to completely remove an electron from a gaseous atom or ion.
• Electron affinity reflects the ability of an atom to accept an electron. It is the energy change that occurs when an electron is added to a gaseous atom.
• Electronegativity is a measure of the attraction of an atom for the electrons in a chemical bond. The higher the electronegativity of an atom, the greater its attraction for bonding electrons.

Overview of Periodic Table

• Alkali Metals (Group 1) : All group 1 metals have one valence electron. When they form ions, they will have a charge of 1+. Group 1 alkali metals are highly reactive and will react vigorously with water.

• Alkali Earth Metals (Group 2): All group 2 metals have two valence electrons. When they form ions, they will have a charge of 2+. Group 2 alkaline earth metals are highly reactive and will react with water.

• Transition Metals (Groups 3–10, d block): Transition metals are famous for the colored salts and colored solutions they form. Many gems contain numerous transition metals. It is hard to predict the charge of a transition metal ion because the transition metals have multiple oxidation states. One transition metal, Hg, exists as a liquid at room temperature.

• Halogens (Group 17): Halogens (salt formers) have seven valence electrons and form ions with a charge of 1−. The halogens exist in three phases at room temperature. Fluorine is a pale-yellow gas, chlorine is a green gas, bromine is a brown-orange liquid, and iodine is a purple solid.

• Noble (Inert) Gases (Group 18): Noble gases have a full outer shell and will not react to form ions or share electrons.

• Lanthanides and Actinides (f Block): These elements have their valence electrons located in the f orbitals and are radioactive in nature.

Alkaline Earth Metals on the Periodic Table

The alkaline earths are the elements located in Group IIA of the periodic table. Alkaline earths metals have low electron affinities and low electronegativities. The alkaline earths have two electrons in the outer shell. They have smaller atomic radii than the alkali metals. The two valence electrons are not tightly bound to the nucleus, so the alkaline earths readily lose the electrons to form divalent cations.

Summary of Common Properties

·         Two electrons in the outer shell

·         Low electron affinities

·         Low electronegativities

·         Readily form divalent cations