Which of the following properties is not a common characteristic of period four transition metals? (A) Good conductivity of heat, (B) luster, (C) brittleness, (D) solidity, or (E) good conductivity of electricity.
The transition metal elements have a similar appearance and similar chemical and physical properties. These elements all exhibit properties that we usually associate with metals. For example, they are typically quite hard, strong, solid, shiny, they have luster, and are good conductors of heat and electricity. These properties make transition metals ideal for things like building structures, forming wires, and more.
Copper has been used to make electrical wiring for more than a century because it is particularly good at conducting electricity and it is not too expensive. Many people also smelted and reformed iron ore to produce mechanically robust metal structures.
Due to their unusual electronic configurations, the transition metals have interesting catalytic properties. Several of them are catalysts for otherwise slow and expensive chemical reactions. We should recall that iron catalyzes the Haber process, and nickel catalyzes the hydrogenation of carbon-carbon double bonds.
Of the properties listed, only one is rare for transition metals, brittleness. None of the period four transition elements are brittle. So the property that is not a common characteristic of period four transition metals is (C) brittleness.