In this video, we will focus on Group 0 elements, which we call the noble gases, and the transition elements, which are the block of metals found in the middle of the Periodic Table.
The elements in Group 0 or Group VIII are called noble gases.
The noble gases are chemically inert, which means they are chemically unreactive elements. They do not react and form compounds or ions. This is because their electronic configurations are stable. They are monatomic, meaning, they exist as single atoms.
All the Group 0 elements are colourless gases at room conditions. They have very low melting and boiling points. They are also insoluble in water.
Noble gases are widely used due to their chemical stability. Helium is used in small balloons and in modern airships because of its low density.
Neon is used in advertising strip lights.
Argon is used in tungsten bulbs. Its chemical stability provides an inert atmosphere to prevent oxidation of the filament.
The transition elements are the block of metals between Group II and Group III of the Periodic Table.
Transition elements have the following properties:
They have high melting points and densities. Tungsten is a transition element and it has the highest melting point of all transition metals. Its melting point is about 3400oC. Due to this, tungsten is a great choice to be used as filaments for bulbs as it does not melt even when it is hot.
They have variable oxidation states in compounds. Iron has oxidation state of +2 and +3 in FeCl2 and Fe2O3 respectively. Manganese has oxidation state of +2, +4 and +7 in MnCl2, MnO2 and KMnO4 respectively.
They form coloured compounds. A solution of its compound is always coloured. The colours of the compounds of a transition metal are different at different oxidation states.
Solutions containing iron(II) ions and iron(III) ions are pale green and yellow respectively.
Copper(I) oxide solid is red while copper(II) oxide is black.
The colour of a hydrated compound may be different from that of the anhydrous compound. Hydrated copper(II) sulfate is blue while anhydrous copper(II) sulfate is white.
Transition elements and their compounds are good catalysts. Catalyst is a substance that speeds up chemical reaction but remains chemically unchanged at the end of the reaction. Iron is a catalyst in the Haber Process for the manufacture of ammonia. Nickel is used in the manufacture of margarine from vegetable oils.
Topic: The Periodic Table, O Level Chemistry, Singapore
If you would like to know more about the basics of Periodic Table, check out this post.
If you would like to know more about Group I elements, check out this post.
If you would like to know more about Group VII elements, check out this post.