Lanthanum :
Define: Lanthanum is inner transition metal place in’ lanthanide series’. It is 1st element in lanthanide series . It show soft, ductile properties and easily cut by knife . It is slightly toxic in nature and rarely found in earth crust. It is found in earth crust in the form of monazite ( contain 25% lanthanum )and bastnaesite( contain 38% lanthanum ) minerals.
Discovery :lanthanum is discovered in 1839 by scientist Carl Gustav Mosander
Origin of name :. The name lanthanum is discovered Greek word ‘ lanthanein’
Meaning of this word is lie
Physical properties :
Atomic symbol: lanthanum is denoted by symbol La
Atomic number : atomic number of lanthanum is 57
In lanthanum 57 proton and 57 neutron is present
Atomic weight/ mass: : atomic weight of lanthanum is 138.9 Amu
In lanthanum 57 proton and 82 neutron is present
Position : lanthanum is place in periodic table at 3th column ( group ) and 6th period ( row)
Block : lanthanum is placed in d block
Colour :lanthanum show silvery white colour
Nature :. Lanthanum present insolid form in nature
Boiling point :boiling point of lanthanum is 3464 0 C
Melting point :melting point of lanthanum is 920 0C
Isotopes: lanthanum show 2 stable isotopes
138La : atomic weight of this isotope is 137.9 Amu
In this isotope 57 proton,57 Electron and 81 neutron is present
It is present 0.09 % in nature
139La : atomic weight of this isotope is 138.9 Amu
In this isotope 57 proton, 57 Electron and 82 neutron is present
It is present 99.9 % in the nature
Chemical properties :
Electronic configuration
Electronic configuration of lanthanum is [ Xe ] 5d1 6S2
Electronic configuration in concert of shell is 2,8,18,18, 9,2
Electronic structure
Valency :valency of lanthanum is 3
Atomic radius : Atomic radius of lanthanum is 230
Reactivity : lanthanum is most reactive metal and handle it be carefully
Burn easily when it is heated
Uses:
Lanthanum oxide is for making special optical glass .
Lanthanum is use as catalyst for petroleum industry
Lanthanum is important component in mischmetalalloy which is use bin flints for cigarette lighter
When it is mixed in nickel alloy use in hydrogen powdered alloy
It’s oxide form use to make camera lenses and special glass
Lanthanum is mixed with other metal and form anode of hydride car batteries
It is added in pools to remove phosphates and stop algae growth .
Question and Answer:
Q1. Define Lanthanum
Q2. Who discovered Lanthanum?
Q2. Physical properties of Lanthanum
Q4. Write Atomic Symbol of Lanthanum.
Q5. Write the Atomic number of Lanthanum.
Q6. On which block Lanthanum element is present?
Q7. What is the color of Lanthanum?
Q8. What is the Boiling point of Lanthanum?
Q9. What is the Melting point of Lanthanum?
Q10. Write the Isotopes of Lanthanum.
Q11. Show Electronic configuration of Lanthanum.
Q12. Write Electronic Structure of Lanthanum.
Q13. What is the Valency of Lanthanum?
Q14. Write the uses of Lanthanum element.