Elements:-Those substances that are made by one type of atom are called elements.
Ex:– Copper, Tin, Silver, gold, Sulphur, Phosphorus, Oxygen, Helium etc.
* Around 118 element exist in nature.
* Out of these, around 92 are natural and rest are man-made elements.
* Among them 2 elements are liquid state-Bromine and Mercury.
* 11 elements are exhibit in gaseous state-hydrogen, oxygen, nitrogen etc
* Most of them are solid in nature. Cesium and Gallium are solid at room temperature but change into liquid when temperature increases.
Type of Element: Metal Non-metal Metalloid
|
Element |
Symbol |
Atomic Number(Z) n(P)=n(E) |
Atomic Weight(A) n(P)+n(N) |
Valency |
|
Hydrogen |
H |
1 |
1 |
1 |
|
Helium |
He |
2 |
4 |
0 |
|
Lithium |
Li |
3 |
7 |
1 |
|
Beryllium |
Be |
4 |
9 |
2 |
|
Boron |
B |
5 |
10 |
3 |
|
Carbon |
C |
6 |
12 |
4 |
|
Nitrogen |
N |
7 |
14 |
3 |
|
Oxygen |
O |
8 |
16 |
2 |
|
Fluorine |
F |
9 |
19 |
1 |
|
Neon |
Ne |
10 |
20 |
0 |
|
Sodium |
Na |
11 |
24 |
1 |
|
Magnesium |
Mg |
12 |
27 |
2 |
|
Aluminium |
Al |
13 |
28 |
3 |
|
Silicon |
Si |
14 |
31 |
4 |
|
Phosphorus |
P |
15 |
32 |
3 |
|
Sulfer |
S |
16 |
35 |
2 |
|
Chlorine |
Cl |
17 |
40 |
1 |
|
Argon |
Ar |
18 |
39 |
0 |
|
Potassium |
K |
19 |
39 |
1 |
|
Calcium |
Ca |
20 |
40 |
2 |
|
Chromium |
Cr |
24 |
52 |
2 |
|
Manganese |
Mn |
25 |
55 |
2, 4 |
|
Iron |
Fe |
26 |
55 |
2, 3, 4 |
|
Cobalt |
Co |
27 |
59 |
2, 3, 4 |
|
Nickel |
Ni |
28 |
58 |
3, 2 |
|
Copper |
Cu |
29 |
63 |
2, 1 |
|
Zinc |
Zn |
30 |
65 |
2 |
|
RADICALS |
SYMBOL |
VALENCY |
|
Hydride |
H |
1- |
|
Hydronium |
H3O |
1+ |
|
Hydroxide |
OH |
1- |
|
Nitrate |
NO3 |
1- |
|
Nitrite |
NO2 |
1- |
|
Permanganate |
MnO4 |
1- |
|
Hydrogen Carbonate/ Bicarbonate |
HCO3 |
1- |
|
Hydrogen Sulfate/ Bisulfate |
HSO4 |
1- |
|
Hydrogen Sulfite/ Bisulfite |
HSO3 |
1- |
|
Ammonium |
NH4 |
1+ |
|
Bromate |
BrO3 |
1- |
|
Bromic Acid |
HBrO3 |
1- |
|
Bromous Acid |
HBrO2 |
1- |
|
Bromite |
BrO |
1- |
|
Chlorate |
ClO3 |
1- |
|
Chlorite |
ClO2 |
1- |
|
Oxide |
O |
2- |
|
Peroxide |
O2 |
2- |
|
Sulfate |
SO4 |
2- |
|
Sulfite |
SO3 |
2- |
|
Silicate |
SiO3 |
2- |
|
Carbonate |
CO3 |
2- |
|
Chromate |
CrO4 |
2- |
|
Dichromate |
Cr2O7 |
2- |
|
Phosphate |
PO4 |
3- |
|
Phosphite |
PO3 |
3- |
|
Borate |
BO3 |
3- |
|
Element |
Symbol |
Latin Name |
|
Antimony |
Sb |
Stibium |
|
Copper |
Cu |
Cuprum |
|
Gold |
Au |
Aurum |
|
Iron |
Fe |
Ferrum |
|
Lead |
Pb |
Plumbum |
|
Mercury |
Hg |
Hydrargyrum |
|
Potassium |
K |
Kalium |
|
Silver |
Ag |
Argentum |
|
Sodium |
Na |
Natrium |
|
Tin |
Sn |
Stannum |
|
Tungsten |
W |
Wolfram |
|
|
Metals (89):-Those elements that are lustrous, sonorous, ductile, malleable, and are good conductor of heat and electricity are called metals.
Ex:-Copper, Tin, Silver, gold etc. All metals are solid except mercury is liquid metal.
Non-metals (22):-Those elementsthat is no-lustrous, non-sonorous, non-ductile, and are bad conductor of heat and electricity are called Non-metals.
Ex:- Sulphur, Phosphorus, Oxygen, Helium, silicon, iodine, carbon, hydrogen, etc.
NOTE- 10 non–metals are solid,1(bromine) is a liquids, 11 are gases.
Metalloids:- Those elements that have properties of both metal and non-metal are called metalloids.
Ex:- Antimony, Germanium, arsenic, silicon etc
Uses of Metals:
* Metals are used for making machines and tools.
* Iron is used for making ships, bridges, railway lines, etc.
* Copper is used for making electric wires.
* Aluminium is used for making utensils, wrapping material,
* Gold and silver and platinum are used for making jewellery.
* Mercury is used in thermometers.
* Nickel and chromium are used for electroplating.
* Lead is used to prepare electrodes in automobile batteries and for making alloys.
Uses of Non-metals:
* Oxygen is used by all living beings for respiration.
* Carbon dioxide is used by plants for photosynthesis.
* Chlorine is used for water purification.
* Iodine solution is used as antiseptic and applied on wounds.
* Coal (carbon) is an important fuel.
* Sulphur is used in the manufacture of matchboxes, gun powder
* Silicon is used to prepare electronic devices, computer device, transistors, microchips, solar cell etc.
* Phosphorusare used to fireworks industry. It is also used in the manufacture of fertilisers.
* Graphite is used as electrodes in dry cells, lubricant and lead of pencils.
Physical Properties of metal and non-metal
|
Property |
Metal |
Non-metal |
|
Malleability |
Metals are malleable, i.e. they can be beaten into thin sheets. |
Non-metals are not malleable. |
|
Conductivity |
Metals are good conductors of heat and electricity. |
Non-metals are bad conductors of heat and electricity. (exception: graphite) |
|
Ductility |
Metals are ductile, i.e. they can be drawn into thin wires. |
Non-metals are not ductile. |
|
Sonorous |
Metals are sonorous, i.e. they produce a typical metallic sound when hit with something. |
Non-metals are not sonorous. |
|
Lustrous |
Metals have metallic shine; called lustre. |
Non-metals are usually dull. (exceptions: diamond and graphite) |
|
Physical State |
Most of the metals are available as solid at room temperature; except mercury and gallium. |
Non-metals are available in all the three states of matter. |
|
Hardness |
Metals are very hard except Sodium and potassium. They are so soft that they can be cut with knife. |
Non-metals are very soft except diamond is very hard known substance. |
Occurrence of Metals:-
* Many metals are found in nature along with impurities. Thus they are very reactive.
* Some metals are found in Free State in nature and they are less reactive hence they are called noble metals. Ex- Gold, Silver, Platinum etc
* The reactive metals are found as chlorides and carbonates. Ex- Calcium chloride, Sodium chloride, Calcium carbonate etc.
* Some metals occur as oxides such as aluminium oxide (Al2O3), iron oxide (Fe2O3)
* Some metals occur as sulphides such as Zinc bled (ZnS), iron sulphide or pyrites (FeS2)
Ores:-Those minerals from which metals can be obtained or extracted economically are called ores.
Gangue:- The impurities present in the minerals are called gangue.
Mining:- The step of processes involved in extracting a metal is called mining.
Occurrence of Non-Metals:-
* .Hydrogen is found in the sun and other stars and also in an important constituent of water.
* Oxygen which is the most abundant element on the earth’s crust, occurs in free as well as combined state. In the Free State oxygen available to all organisms for respiration and also support in the process of combustion. In combined state oxygen is an important constituent of water that is useful for aquatic animals.
* Nitrogen occurs in free state in air and in combined form in nitrate of other elements.
Chemical Properties of Metals and Non-metals
Reaction with Oxygen
Metals react with oxygen to form metallic oxides. Metallic oxides are basic in nature.
Example:- Iron reacts with oxygen and moisture to form iron oxide. Iron oxide is brown in colour and is commonly known as rust.
Fe + O2 + H2O → Fe2O3
Example:- Magnesium reacts with oxygen when it is burnt and forms magnesium oxide.
Mg + O2 → 2MgO
Example:Sodium metal reacts with oxygen of air to form basic oxide called sodium oxide.
4Na + O2 → 2Na2O
NOTE:-Sodium and potassium metals are highly reactive, they react vigorously with the oxygen (or air).They catch fire and start burning when kept open in the air. So, they are stored in kerosene to prevent their reaction with oxygen, moisture and CO2 of air.
Non-metals also react with oxygen to make oxides. Oxides of non-metals are acidic in nature.
Example:- 1. Sulphur reacts with oxygen when it is burnt. It forms sulphur dioxide.
S + O2 → SO2
When sulphur dioxide is dissolved in water, it forms sulphurous acid.
SO2 + H2O → H2SO3
2. Carbonreacts with oxygen of air to form carbon dioxide gas.
C + O2 → CO2
When carbon dioxide is dissolved in water to form carbonic acid.
CO2 + H2O → H2CO3
Reaction with water
Some metals react vigorously with water, while some others do not react at all with water.
Example:- Sodium is a highly reactive metal and reacts vigorously with water. This is a highly exothermic reaction. During this reaction; sodium catches fire because of too much heat being evolved. Due to this, sodium is stored in kerosene to prevent accidental fire.
* Iron reacts slowly with water.
* Copper does not react with water but reacts with steam.
* Silver and gold do not react with water at any temperature.
Usually, non-metals do not react with water; but some non-metals react vigorously (prabalata se) with air. Such non-metals are stored in water to prevent their reaction with air. For example; phosphorus is stored in water to prevent its reaction with air.
Reaction with Acids
Metals generally react with acids and produce hydrogen gas with a ‘pop’sound. Confirmation of hydrogen gas is done by bringing a burning matchstick or a burning candle near the gas. When the burning matchstick or candle burns with a pop sound it confirms the evolution of hydrogen gas.
Metal + Acid → Salt + Hydrogen
* Copper does not react with even concentrated hydrochloric acid. However, copper reacts with sulphuric acid.
* Sodium react with hydrochloric acid to form sodium chloride and hydrogen.
2Na +2HCl →2NaCl +H2
* Zink react with hydrochloric acid to form Zink chloride and hydrogen.
Zn +2HCl →ZnCl2 +H2
* Non-metals generally do not react with acids.
Reaction with Bases
Metals react with sodium hydroxide to produce hydrogen gas.
Metal + Sodium hydroxide → Hydrogen
Non-metals’ reaction with sodium hydroxide is much complex.
Displacement reactions and Reactivity series:-
|
Chemical reaction in which a more reactive metal replaces another less reactive metal from salt solution is called displacement reaction. In this reaction, a more reactive metal displaces a less reactive metal from a compound. Reactivity Series:-Arrangement of metals in order of decreasing reactivity is called reactivity series of metals. Most reactive metal(Sodium) is placed on top of the reactivity series and least(Gold) at the bottom of reactivity series. Example:- When zinc are kept in copper sulphate solution, the blue colour of copper sulphate solution changes colourless and a reddish deposit of copper is formed on the surface of zinc. CuSO4 + Zn → ZnSO4 + Cu The above reaction is chemical displacement reaction in which a more reactive metal (zinc) displaces less reactive metal (copper) from its salt solution (copper sulphate). The solution becomes colourless because zinc sulphate solution forms a colourless solution. But when copper are kept in zinc sulphate solution, no reaction takes place. ZnSO4 +Cu →No reaction as copper is less reactive than zinc. Example:- When iron nails are kept in copper sulphate solution, the blue colour of copper sulphate solution changes to light green colour and reddish deposit of copper is formed on the surface of iron. CuSO4 + Fe → FeSO4 + Cu The above reaction is chemical displacement reaction in which a more reactive metal(Iron) displaces less reactive metal (copper) from its salt solution(copper sulphate). The green colour of the solution is due to the formation of ferrous sulphate (iron sulphate). But when copper turnings are kept in iron sulphate solution, no reaction takes place. FeSO4 +Cu →No reaction as copper is less reactive than iron. |
Elements |
Reactivity |
|
Potassium(K) Sodium(Na) Barium(Ba) Calcium(Ca) Magnesium(Mg) Aluminium(Al) Zinc(Zn) Iron(Fe) Nickel(Ni) Tin(Sn) Lead(Pb) Hydrogen(H) Copper(Cu) Mercury(Hg) Silver(Ag) Gold(Au)
|
Decreases
|