Class 10 Metallurgy notes ICSE CHEMISTRY

Metallurgy Notes - Important points for Board exam

Metal: Metal is an element which ionizes by losing one or more electrons.

ü Metals have 1,2 or 3 electrons in their valence shell.

ü They lose electrons and form positive ions (cations) hence they form electrovalent compounds.

Na – e^- --> Na⁺

Mg – 2e^- --> Mg²⁺

Al – 3e^- --> Al³⁺

Physical properties:

Metals	Non-metals
1. Exist in solid state at room temp. Except: Mercury is liquid, Gallium melts at room temp.	1. Exist as soft solids and gases. Except: Bromine is liquid at room temp.
2. Have luster	2. Do not have luster. Except: Iodine crystals, Diamond and Graphite shine
3. Have high boiling and melting points. Except: Na, K, Hg etc	3. Have low boiling and melting points. Except: Carbon, Silicon.
4. High density. Except Na, K, Ca	4. Low density except Diamond.
5. Are malleable and ductile except zinc and Mercury	5. Non-Malleable and non-ductile except Carbon fibre.
6. Non- brittle but Zinc is brittle.	6. Non-metals are brittle.
7. Good conductors of electricity except Tungsten.	7. Non-conductors except Graphite and gas Carbon.

Metals	Non-metals
1. Have 1, 2 or 3 valence electrons.	1. Have 4, 5, 6 or 7 valence electrons.
2. They form cations by losing electron/s. And Reducing agents (donate electrons)	2. Form anions by gaining electron/s. And Oxidizing agents (accept electrons).
3. Electropositive elements.	3. Electronegative elements.
4. During electrolysis cations gain electrons (get reduced) and are discharged.	4. Anions lose electrons (get oxidized) and are discharged.
5. Active metals react with dil. acids to liberate Hydrogen gas. Reason: active metal can transfer electrons to the Hydrogen ions of acids and neutralize them to atoms.	5. Non-metals do not give Hydrogen gas with dil. acids. Reason: Electron transfer does not take place from the non-metals to the Hydrogen ion of the acid.
6. Metal oxides are basic in nature. (Al₂O₃, ZnO and PbO are amphoteric in nature).	6. Non-metallic oxides are acidic in nature and form acids when dissolved in water. (CO, NO,N₂O, H₂O are neutral oxides)
7. Metal chlorides are solids and non-volatile. Electrovalent compounds.	7. Non-metallic chlorides are volatile liquids. Covalent compounds