Transition-metal properties, oxidation states and colours

By the end you’ll be able to

• Define a transition element in terms of formation of at least one stable ion with an incomplete $d$ subshell, and distinguish transition metals from $d$-block elements that do not meet this definition.
• Describe and explain the characteristic physical properties of transition metals, including relatively high melting points, high densities, strength, and catalytic behaviour, in terms of metallic structure and electron arrangement.