Explain the meaning of a transition element.
Describe the colour change observed when excess $\text{Sn}^{2+}$(aq) is added separately to • dilute acidified $\text{MnO}_{4}^{-}$(aq) (from \_\_\_\_\_\_\_ to \_\_\_\_\_\_\_), and • dilute acidified $\text{Cr}_{2}\text{O}_{7}^{2-}$(aq) (from \_\_\_\_\_\_\_ to \_\_\_\_\_\_\_).
Write an equation to show the reaction between $\text{Sn}^{2+}$(aq) and acidified $\text{Cr}_{2}\text{O}_{7}^{2-}$(aq).
State what a co-ordination number of six means.
State the formula of X, including its charge.
Draw the two isomeric forms of X. Your diagrams should show the three-dimensional shapes of the two isomers and the way each ligand is attached to the central ruthenium ion.
Suggest the type of isomerism shown by X.
Explain where the colour in a transition element complex such as X comes from.