write down all the exceptionals metals and nonmetals and their exceptionals properties
Answers
PHYSICAL PROPERITES OF METALS:-
1. Generally metals are hard.
Exception – sodium and potassium. It is so soft that it can cut with a knife.
2. Metals are found in solid state exception – mercury exists in liquid state.
3. The boiling point and melting point of metals are high.
Exception – sodium and potassium. Gallium cesium
4. Its density is high.
Exception – sodium and potassium.
5. It is sonorous.
Exception – Mercury
SONOSITY:-When a metal is beaten it produces sound, this property of metal is called its sonority.
6. It is malleable.
Exception – Mercury
MALLEABILITY:-
A metal can be changed into a thin sheet by hammering this property of metal is called malleability.
- Aluminum is the best malleable metal.
7. It is ductile.
Exception – mercury.
DUCTILITY
A metal can be changed into a thin wire this property of metal is called ductility.
- Gold and silver are the best ductile metal.
. It a good conductor of heat.
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CHEMICAL PROPERTIES OF METALS
What happens when metals are burnt in air?
- Almost all metals combine with oxygen to form metal oxide.
METAL + OXYGEN – METALOXIDE
e.g. 2Na + O2 – 2NaO
2Cu + O2 – 2CuO (a black oxide)
4Al + 3O2 – 2Al2O3
- Generally, metal oxides are basic in nature. But some metal oxides are both acidic as well as basic in nature.
- Such metal oxides which react with both acids as well as bases to produce salts and water are known as amphoteric oxides.
e.g. AL2O3 + 6HCl – 2AlCl3 + 3H2O
Al2O3 + 2NaOH – 2NaALO2 + H2O
(Sodium aluminate)
- Most metal oxides are insoluble in water but some of these dissolve in water to form alkalis.
e.g. Na2O(s) + H2O(l) – 2NaOH(aq)
K2O(s) + H2(l) – 2KOH(aq)
- physical properties of non metals..
Now, let us glance through some physical properties of non-metals. Physical properties alone are not good for distinguishing non-metals due to exceptions in almost every physical property. Later, we shall study in more detail chemical properties, which is the best way to differentiate between metals and non-metals.
State of existence: Non-metals usually exist in the three states of matter. However, most of them exist in gaseous form. Non-metals like nitrogen, oxygen, carbon dioxide, argon, neon, helium, krypton, chlorine, and fluorine are the ones which constitute the air in our surroundings.
Hardness: Out of all the non-metals, only solids are expected to be hard. Sulphur and phosphorus are quite soft, but diamond is very hard. Diamond is also probably the hardest substance presently known
Lustre: Non-metals usually have no shine since they have no loosely attached electrons which are responsible for lustre. However, there are exceptions. Out of the non-metals, Diamond and iodine have lustrous nature.
Lustrous Iodine: An exception for Lustre
Electrical and Thermal Conductivity:Non-metals, in general, are quite poor conductors of heat and electricity. Graphite is an exception here.In fact, it is a very good conductor of electricity.
Malleability: Non-metals cannot be beaten into thin sheets in the way that metals can. There is a weak force of attraction. As a result, they are quite brittle. Sulphur is a brittle element. If it is hammered, it would break into pieces.
Ductility: Non-metals cannot be drawn into thin wires. They would break, whether being beaten into thin sheets or drawn into wires.
Sonorosity: Non-metals are not sonorous. They produce no ringing sound when struck on their surface.
Chemical Properties of non metals...
Reaction with Oxygen: In the presence of oxygen, when non-metals are heated they react and form non-metal oxides. These oxides are generally acidic in nature. In general, they react in the following manner:
Reaction with Acids: Non-metals, being electronegative, do not react with dilute acids as they cannot displace hydrogen easily. However, they react with concentrated acids when they are heated. Here's the general formula:
However, the salt may not necessarily be formed in all the cases.
Reaction with Chlorine: Non-metals react with chlorine atoms upon heating to form their respective chlorides. Sulphur and phosphorus react in this way. Let's have a look at some reactions to have a better idea of this.
Reaction with hydrogen: Non-metals form their respective hydrides when they react with hydrogen. These hydrides are non-electrolytic and exist as gases at room temperature. This is the general formula:
Reaction with Salt Solutions: This type of reaction is similar to the one we discussed in the chemical properties of metals. Here again, the reactions involve the reactivity series. A non-metal which is higher in the series can displace a non-metal from it's salt which is lower than it. Here's the general formula:
provided that the reactivity of Metal A is greater than the reactivity of Metal B.