The telluric helix was given by:
1. Newland
2. Mendeleev
3. Lothar Meyer
4. De-chancourtois
The element with atomic number 30 is expected to be present in:
1. IB group
2. IA group
3. IIA group
4. IIB group
Which among the following elements is the bridge element?
1. K
2. O
3. Mg
4. Pb
Four successive members of the first-row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionisation enthalpy?
1. Vanadium (Z = 23)
2. Chromium (Z = 24)
3. Iron (Z = 26)
4. Manganese (Z = 25)
Transition elements show:
1. variable valency
2. paramagnetism
3. catalytic properties
4. all of these
The transition elements are more metallic than the representative elements because they have:
1. The electrons in d-orbitals
2. Electron pairs in d-orbitals
3. Availability of d-orbitals for bonding
4. Unpaired electrons in metallic orbitals
Which pair has elements containing a same number of electrons in the outermost orbit?
1. N, O
2. Na, Ca
3. As, Bi
4. Pb, Sb
The correct arrangement of increasing order of atomic radius among Na, K, Mg and Rb is
1. Mg<K<Na<Rb
2. Mg<Na<K<Rb
3. Mg<Na<Rb<K
4. Na<K<Rb<Mg
Which of the following statement is correct with respect to the property of elements with increase in atomic number in carbon family.
1. Their metallic character decreases
2. The stability of +2 oxidation state increases
3. Their ionisation energy increases
4. Their atomic size decreases