Question

In: Chemistry

Why do lanthanoid ions have similar chemical properties even with variation of atomic number and have...

Why do lanthanoid ions have similar chemical properties even with variation of atomic number and have higher lifetime in excited states than transition metal ions ??

Solutions

Expert Solution

Chemical properties of elements depend on the size of their ions, in periodic table size of atoms decreases from left to right with increase in atomic number.

In case of lanthanoids the atomic and ionic radaii decrease gradually from lanthanum to lutetium. This decrease in the atomic and ionic size along the lanthanoid seriess is known as Lanthanoid contraction.

The decrease in size from one element to the other element is smaller than that observed in case of transition series element. The decrease in size is attributed to the poor shielding effect from f electron in the second inner shell.

Therefore in lanthanoid elements difference in size from one element to the next is smaller, so they have similar chemical properties.

In case of lanthanoids the inner most f electrons gets excited when energy is supplied, this f electron are buried very much inside, so they are not affected by external environment and hence they have higher lifetime in excited state than transition metal ions.


Related Solutions

The metals Cadmium and Mercury are similar in their chemical properties, but in terms of their...
The metals Cadmium and Mercury are similar in their chemical properties, but in terms of their absolute entropy at room temperature and pressure, they are very different. Why?
How can enatiomers have the same chemical and physical properties- even have the same systematic name-...
How can enatiomers have the same chemical and physical properties- even have the same systematic name- but be completely different compunds? I am a little confused on this.
1.Does each amino acid have the same chemical properties? Why or why not? 2.How do only...
1.Does each amino acid have the same chemical properties? Why or why not? 2.How do only 4 different RNA nucleotides code for 20 different amino acids? 3.   How does a start codon differ from a stop codon? Do they possess any similarities
Substances have both chemical properties andphysical properties. A)Which of the following properties of aluminum are chemical...
Substances have both chemical properties andphysical properties. A)Which of the following properties of aluminum are chemical properties? In moist air it combines with oxygen to form aluminum oxide. It is a shiny, silvery white metal. It reacts with chlorine to form aluminum chloride It has a mass of 26.98 g. B)Which of the following properties of a piece of wood are physical properties? It has a mass of 2.3 g. It is rough to touch. It is hard. In burns...
The polypeptide sequence below has three continuous regions in which the residues have similar chemical properties....
The polypeptide sequence below has three continuous regions in which the residues have similar chemical properties. Identify these and very briefly describe their properties:  DKEKRESNQYTMLVFI
Which of the following describes an atom or group of atoms that has similar chemical properties...
Which of the following describes an atom or group of atoms that has similar chemical properties when it occurs in different compounds? A. functional group B. isomer C. isotopes D. hydrocarbons
4. Which two electron configurations represent elements that would have similar chemical properties? (1) 1s22s22p4       (2)...
4. Which two electron configurations represent elements that would have similar chemical properties? (1) 1s22s22p4       (2) 1s22s22p5       (3) [Ar]4s23d5       (4) [Ar]4s23d104p5 A) (1) and (2) B) (1) and (3) C) (2) and (3) D) (2) and (4) E) (3) and (4) 5. Which of the following make an isoelectronic pair: Cl–, O2–, F, Ca2+, Fe3+? A) Ca2+ and Fe3+ B) O2– and F C) F and Cl– D) Cl– and Ca2+ E) None of the above. 6. Which of the...
PT1. Oxygen and sulfur have similar chemical properties due to having six valence electrons.  Both form molecules...
PT1. Oxygen and sulfur have similar chemical properties due to having six valence electrons.  Both form molecules with two hydrogen atoms.  Surprisingly, water (H2O) is a liquid, yet H2S is a gas, even though sulfur is much larger and heavier than oxygen.  Why? Explain fully. PT2. The ion product of water, Kw=[H+][OH-] = 0 x10-14  (3 points) Why is a solution at pH 7.0 said to be neutral? What is the H+ concentration and pH of a 1mM solution of NaOH? If the pH...
Group the following electron configurations in pairs that would represent similar chemical properties of their atoms:...
Group the following electron configurations in pairs that would represent similar chemical properties of their atoms: 1s22s22p63s2 1s22s22p3 1s22s22p63s23p64s23d104p6 1s22s2 1s22s22p6 1s22s22p63s23p3
Elements that appear in the same column of the periodic table often share similar chemical properties....
Elements that appear in the same column of the periodic table often share similar chemical properties. In the case of the alkaline earth metals, this is troublesome since the body treats calcium (necessary for proper bone growth) and radium (a radioactive element) as chemically similar, storing both in bone marrow. The radium then bombards nearby bone cells with alpha particles, causing them to "crumble." Radium poisoning investigations often center on the identification of radium and its isotopes in bone samples...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT