Class 10 (Metals and non metals)

Metals And Non metals notes

CLASS- X

16-August-2021

TEXT-1

Metals and Non-metals

Elements can be classified into the following two groups depending on their physical and chemical properties:

1. Metals
2. Non-metals

Metalloids:

The elements which possess the properties of metals and non-metals are called metalloids.
For example: boron, silicon, germanium, tellurium, arsenic and antimony are metalloids.

TEXT-2

Chemical properties of Metals and Non-metals:

Reaction with oxygen:

Reaction of metals with oxygen:

Metals react with oxygen under different conditions to form basic oxides. These basic oxides react with water to form bases which turn red litmus into blue.
Sodium and potassium react with oxygen vigorously at room temperature.
4Na    +     O₂        --->                   2Na₂ O
To prevent this oxidation, sodium and potassium are stored under kerosene.
agnesium reacted with oxygen only if ignited. It gives a bright dazzling flame and forms a white powder of magnesium oxide.
2Mg    +     O₂       ---->                    2MgO
Iron metal does not burn in dry air even on strong heating. In moist air, iron get oxidise to form iron oxide (rust)
4Fe    +     3O₂      ------>                     2Fe₂ O₃
Fe₂ O₃    +  nH₂ O     ------>                 Fe₂ O₃  nH₂ O

Reaction of non-metals with oxygen:

Non-metals react with oxygen to form acidic or neutral oxides.
C    +     O₂         ---->                      CO₂
S   +     O₂           ----->                     SO₂
Other oxides like carbon monoxide (CO) and nitrous oxide (N2O) are neutral.

TEXT-3

Reaction with water:

Reaction of metal with water:

etal react with water to form oxides or hydroxides along with hydrogen. Different metals react at different temperature.
Sodium, potassium and calcium react vigorously with cold water to form metal hydroxides.
2Na    +     2H₂O       ----->                    2NaOH  + H₂
etal from magnesium to iron react with steam (but not water) to form metal oxide and hydrogen gas.
2Mg    +    H₂O         ----->                  2MgO  +  H₂
Tin, lead, copper, silver and gold do not react with water or steam.

Reaction of non-metal with water:

Non-metals do not generally react with water.

Reaction with dilute acids:

Reaction of metals with dilute acids:

Metals react with dilute acids to form their salt and liberate hydrogen gas. The evolution of hydrogen gas can be tested by bringing a burning splinter near the mouth of the test tube. Hydrogen gas will put off the splinter with a pop sound.
2Na    +     2HCl          ------>                 2NaCl  + H₂
Zn    +    H₂SO₄       ------>                 ZnSO4  + H₂
etals below hydrogen (copper, silver, gold and platinum) do not react with dilute acids as they are less reactive than hydrogen. So they cannot displace hydrogen from dilute acids.

Reaction of non-metals with dilute acids:

Non-metals do not react with dilute acids.

Displacement reactions:

A more reactive metal displaces a less reactive metal from its compound in aqueous solution. Such a reaction is known as displacement reaction.
For example: When iron nail put in copper sulphate solution then colour of solution changes from blue to light green and a reddish brown coating of copper is seen on iron nail.
Fe    +     CuSO₄      --->                     FeSO₄   +    Cu
Iron         copper sulphate           iron suphate    copper
                  (blue)                             (green)
Iron sulphate   +    copper                    no reaction
Because copper is less reactive than iron so cannot displace it.