Test: Classification of Elements and Periodicity in Properties (May 12) - JEE MCQ

Alkali metals always form ionic bonds.

vanderwaal radius > Metallic radius > Covalent radius.

Density: Li < Na < K < Rb.
The density of K is lower than that of Na. Thus, option D is incorrect. The correct trend is
Li < K < Na < Rb

Dmitri Mendeleev and Lothar Meyer proposed arranging elements in 1. increasing order of their atomic weights. This arrangement eventually led to the development of the periodic table of elements.

they are numbered from 1 to 18 1 is alkali metal group and 18 is noble gases.

as we move from left to right in a period atomic radii decreases and due to effective nuclear charge outermost electrons are held more closely to the nucleus.

As the size increases bond length also increases.

Mn has most stable +2 stable because Mn+2 had d5 configuration which is most stable.

When a transition metal ion is in highest oxidation state it tends to lower its oxidation state by gaining electrons. thus it itself reduces and oxidizes the substance from which it accepts electron. So, it acts as oxidising agent. 

Smaller the size of cation, higher will be the hydration and its effective size will increase and hence mobility in aqueous solution will decrease. Larger size ions have more ionic mobility due to less hydration. Thus the degree of hydration of M⁺ ions decreases from Li⁺ to Cs⁺. Consequently the radii of the hydrated ion decreases from Li⁺ to Cs⁺. Hence the ionic conductance of these hydrated ions increases from Li⁺ to Cs⁺ 

electronegativity increases on moving from left to right while decreases as we move down the group.

They are isoelectronic species with same number of electrons. Higher is the atomic number, higher will be the effective nuclear charge, lower will be the size.

Na and Mg are not an exception.

Cl just need one more electrons to get fully filled electronic configuration so it has most negative electron gain enthalpy while P has d3 configuration which is already stable so it cannot accept one electron extra easily so have large positive electron gain enthalpy.

sept is for 7.