Number of elements from the following that CANNOT form compounds with valencies which match with their respective group valencies is ________. B, C, N, S, O, F, P, Al, Si
Statement (I) : Both metals and non-metals exist in p and d-block elements.
Statement (II) : Non-metals have higher ionisation enthalpy and higher electronegativity than the metals.
In the light of the above statements, choose the most appropriate answer from the options given below :
Consider the following elements.
Which of the following is/are true about $$\mathrm{A}^{\prime}, \mathrm{B}^{\prime}, \mathrm{C}^{\prime}$$ and $$\mathrm{D}^{\prime}$$ ?
A. Order of atomic radii: $$\mathrm{B}^{\prime}<\mathrm{A}^{\prime}<\mathrm{D}^{\prime}<\mathrm{C}^{\prime}$$
B. Order of metallic character: $$\mathrm{B}^{\prime}<\mathrm{A}^{\prime}<\mathrm{D}^{\prime}<\mathrm{C}^{\prime}$$
C. Size of the element: $$\mathrm{D}^{\prime}<\mathrm{C}^{\prime}<\mathrm{B}^{\prime}<\mathrm{A}^{\prime}$$
D. Order of ionic radii: $$\mathrm{B}^{\prime+}<\mathrm{A}^{1^{+}}<\mathrm{D}^{\prime+}<\mathrm{C}^{+}$$
Choose the correct answer from the options given below :