Periodic classification of elements and their trends

The second ionisation energy order is correct for which of the following

• O > N

• N > O

• Na<N

• Na<O

Choose the correct statement(s) among the following about d block elements:

• They have non varying oxidation states

• They form catalysts

• They form interstitial hydrides

• They form coloured compounds often

There is an increase in +2 oxidation state stability when we move along a group. Name the effect which causes this.

Which of the following elements is not in its ground state?

• [Ar] 3d10 4s1

• [Ar] 3d5 4s1

• [He] 2s2 2p3

• [He] 2s1 2p3

The following factor is greater for Ca and lower for Na

• IE2

• IE1

• Ionic radii

• e/p ratio

Whose work gave idea that classification of elements should not be done on the basis of atomic mass/weight?

• Hysenberg

• Moseley

• Rutherford

• Mendeleev

Name the element which is a metal and liquid at room temperature.

Ca2+ is smaller than K+ because

• High nuclear charge

• Inert pair effect

• Less no. of protons more will be the IE

• None of the above

The Ionisation energy and Acidity _______________ and ___________________ along a group.

• increases, decreases

• decreases, remains same

• remains same, increases

• decreases, increases

Element X forms a chloride with the formula XCl2, which is a solid with a high melting point.

X would most likely be in the same group of the periodic table as ___________

• Na

• Mg

• Al

• Si