Video Transcript
Which of the following properties
is not true for transition elements? (A) Transition elements form
compounds with catalytic activity. (B) Transition elements have high
melting and boiling points. (C) Transition elements show
variable oxidation states. (D) Transition elements form
compounds that are often diamagnetic. (E) Transition elements form
colored ions and compounds.
Transition elements are the
elements found in the d block in the middle of the periodic table. Transition elements include metals
like vanadium, iron, manganese, and copper. Let’s take a look at these answer
choices one by one to determine which one is not true for transition elements.
Choice (A) is incorrect. Transition elements do form
compounds with catalytic activity. For example, vanadium oxide
catalyzes part of the contact process, which produces sulfur trioxide that
eventually forms sulfuric acid.
Choice (B) is incorrect as
well. Transition elements do have high
melting and boiling points. For example, iron’s melting point
is 1538 degrees Celsius, while its boiling point is 2862 degrees Celsius.
Choice (C), transition elements
show variable oxidation states, is also a true statement. For example, manganese’s oxidation
state in manganese oxide is plus two, while in potassium permanganate, it’s plus
seven. In its elemental form, its
oxidation state is zero.
Choice (E) is also a true
statement. For example, the nickel ions in a
nickel chloride solution give it a green color, while cobalt forms the compound
cobalt chloride, which has a deep blue color.
The last remaining answer choice,
choice (D), is the correct answer. Most transition elements form
paramagnetic compounds, meaning they will be attracted by a magnet. Although some compounds with
transition elements, such as cuprous chloride, are diamagnetic and are not attracted
by magnets, these compounds are relatively rare.
So which of the following
properties is not true for transition elements? That’s choice (D). Transition elements form compounds
that are often diamagnetic.
