Introduction :
Beryllium is the compound which as atomic number 4 and mass number 9.01218. Beryllium has electronic configuration 1s2, 2s2. Beryllium has oxidation state +2. Group 2 elements are Be, Mg, Ca, Sr, Ba, Ra are alkaline earth elements. Atomic number 4 is a exception : it does not react with water or steam, and its halides are co-valent bond with beryllium. All the alkaline earth metal as two electrons in the outermost shell, so filled electron shell is achieved by the lose of two electrons to form doubly charged positive ions. Atomic number 4 is a bivalent element. It is found naturally only combined with other minerals. Notable gemstone which has Atomic number 4 include beryl (aquamarine, emerald) and chrysoberyl. Atomic number is a steel – gray, strong, light weight brittle alkaline earth metal.
Beryllium (White grey metal).
1) Atomic Radius of Group 2 elements: Atomic radius increases down the group. Atomic radius of Ra is less than Ba.
Where A.R. = Atomic Radius in pico metre.
2) Density of beryllium is 1.848g/cm3.
3) Ionisation energy (I.E.) of Atomic number 4:
1st I.E. = 899.5 KJ/mol.
2nd I.E. = 1757.7 KJ/mol.
3rd I.E. = 14848.7KJ/mol.
3rd I.E. is very large because the electron is present near to the nucleous and strongly binded to the nucleous. Therefore it requires more energy to remove that electron which is ns2 configuration.
4) Elecrtropositive character of Group 2 elements: Electropositive character increases down the group.
5) Metallic properties of Atomic number 4: Atomic number 4 has low density (1.85 times that of water), high melting point= 12870C. High temperature stability and low co-efficient of thermal expansion, These conditions is suitable for aerospace material, Atomic number 4 is a important component of planned space telescope because of its relatively high transparency to X-ray.
6)Reaction of Atomic number 4 with air: Beryllium does not burn unless it is in the form of dust or powder. Be has a thin layer of Beryllium oxide on its surface which prevent any new oxygen getting at the underlying Be to react.
2Be(s) + O2(g) → 2BeO(s)
7) Diagonal relationship of Atomic number 4: Beryllium shows diagonal relationship with Aluminium. It is the similarity between the first element of a group with the second element in the next higher group.
8) Ores of Beryllium:
a) Betrandite (Be4si2O7(OH)2)
b) Beryl (Al2Be3Si6O18)
c) Chrysoberyl (Al2BeO4)
d) Phenakite (Be2SiO4)
Precious form of Beryl are aquamarine, bixbite and emerald.
Beryllium is the compound which as atomic number 4 and mass number 9.01218. Beryllium has electronic configuration 1s2, 2s2. Beryllium has oxidation state +2. Group 2 elements are Be, Mg, Ca, Sr, Ba, Ra are alkaline earth elements. Atomic number 4 is a exception : it does not react with water or steam, and its halides are co-valent bond with beryllium. All the alkaline earth metal as two electrons in the outermost shell, so filled electron shell is achieved by the lose of two electrons to form doubly charged positive ions. Atomic number 4 is a bivalent element. It is found naturally only combined with other minerals. Notable gemstone which has Atomic number 4 include beryl (aquamarine, emerald) and chrysoberyl. Atomic number is a steel – gray, strong, light weight brittle alkaline earth metal.
Beryllium (White grey metal).
1) Atomic Radius of Group 2 elements: Atomic radius increases down the group. Atomic radius of Ra is less than Ba.
| Element | Be | Mg | Ca | Sr | Ba | Ra |
| A.R.(pm) | 112 | 160 | 197 | 211 | 222 | 215 |
2) Density of beryllium is 1.848g/cm3.
3) Ionisation energy (I.E.) of Atomic number 4:
1st I.E. = 899.5 KJ/mol.
2nd I.E. = 1757.7 KJ/mol.
3rd I.E. = 14848.7KJ/mol.
3rd I.E. is very large because the electron is present near to the nucleous and strongly binded to the nucleous. Therefore it requires more energy to remove that electron which is ns2 configuration.
4) Elecrtropositive character of Group 2 elements: Electropositive character increases down the group.
5) Metallic properties of Atomic number 4: Atomic number 4 has low density (1.85 times that of water), high melting point= 12870C. High temperature stability and low co-efficient of thermal expansion, These conditions is suitable for aerospace material, Atomic number 4 is a important component of planned space telescope because of its relatively high transparency to X-ray.
6)Reaction of Atomic number 4 with air: Beryllium does not burn unless it is in the form of dust or powder. Be has a thin layer of Beryllium oxide on its surface which prevent any new oxygen getting at the underlying Be to react.
2Be(s) + O2(g) → 2BeO(s)
7) Diagonal relationship of Atomic number 4: Beryllium shows diagonal relationship with Aluminium. It is the similarity between the first element of a group with the second element in the next higher group.
8) Ores of Beryllium:
a) Betrandite (Be4si2O7(OH)2)
b) Beryl (Al2Be3Si6O18)
c) Chrysoberyl (Al2BeO4)
d) Phenakite (Be2SiO4)
Precious form of Beryl are aquamarine, bixbite and emerald.
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