CBSE
Which of the following has largest atomic radii ?
Al
Al+
Al2+
Al3+
The pair of amphoteric hydroxides is
Be(OH)2, Al(OH)3
Al(OH)3, LiOH
B(OH)3, Be(OH)2
Be(OH)2, Mg(OH)2
Assertion: The correct order of oxidising power is :
<
Reason: The oxidation state of Mn is +7
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Which of the following is correct?
Ionic radius is proportional to atomic number.
Ionic radius is inversely proportional to atomic mass.
Ionic radius is inversely proportional to effective nuclear charge.
All are correct.
Assertion : Helium is used in diving apparatus.
Reason : Solubility of helium is less in blood.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Assertion : The position of an element in periodic table after emission of one and two - particles remains unchanged.
Reason : Emission of one and two particles give isotope of the element which acquires same position in periodic table
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Maximum number of unpaired electrons are present in
Gd3+
Yb2+
Tb2+
Pm3+
Which of the following element has lowest melting point?
Cr
Fe
Ni
Cu
Ionisation potential is lowest for :
alkali metals
inert gases
halogens
alkaline earth metals
Beryllium and aluminium exhibit many properties which are similar. But the two elements differ in
maximum covalency in compounds
exhibiting amphoteric nature in their oxides
forming covalent halides
forming polymeric hydrides