Tue June 12, 2012 By: Prkriti Gupta

why the mealting point increases upto arsenic give reason and then decreases upto bismuth? what do we mean by oxidation state?

Expert Reply
Wed June 13, 2012
The melting point increases upto arsenic and then decreases upto bismuth due to the presence of completely filled d and/or f orbitals. Going down the group, the principal quantum number increases and hence the melting point decreases because of the poor shielding effect of f - electrons and hence the attraction between the nucleus and the outermost electrons decreases.
The oxidation state of an element is related to the number of electrons that an atom loses, gains, or appears to use when it joins with another atom in compounds. It is a measure of the degree of oxidation of an atom in a substance.
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