91Ó°ÊÓ

Briefly account for each of the following observations: (a) Atomic radii decrease in the order \(\mathrm{Sc}>\mathrm{Ti}>\mathrm{V}\). (b) Densities increase in the order \(\mathrm{Ti}<\mathrm{V}<\mathrm{Cr}\).

Arrange the following atoms in order of decreasing atomic radius, and account for the trend: (a) \(\mathrm{Cr}\) (b) \(\mathrm{Ti}\) (c) \(\mathrm{Mn}\) (d) \(\underline{V}\)

What is the lanthanide contraction, and why does it occur?

The atomic radii of zirconium ( \(160 \mathrm{pm}\) ) and hafnium (159 \(\mathrm{pm}\) ) are nearly identical. Explain.

Which element is more easily oxidized, Ti or Zn?

Write a balanced net ionic equation for the reaction of each of the following metals with hydrochloric acid in the absence of air. If no reaction occurs, indicate N.R. (a) \(\mathrm{Cr}\) (b) \(\mathrm{Zn}\) (c) \(\overline{\mathrm{Cu}}\) (d) \(\mathrm{Fe}\)

Write a balanced net ionic equation for the reaction of each of the following metals with dilute sulfuric acid in the absence of air. If no reaction occurs, indicate N.R. (a) \(\mathrm{Mn}\) (b) \(\mathrm{Ag}\) (c) \(\mathrm{Sc}\) (d) \(\mathrm{Ni}\)

Which of the following metals have more than one oxidation state? (a) \(\mathrm{Zn}\) (b) \(\mathrm{Mn}\) (c) \(\mathrm{Sr}\) (d) \(\overline{\mathrm{Cu}}\)

Which of the following metals have only one oxidation state? (a) \(\underline{V}\) (b) \(\mathrm{Al}\) (c) Co (d) Sc

What is the highest oxidation state for each of the elements from Sc to \(\mathrm{Zn} ?\)