Which One Of The Following Is Improperly Labeled?
A He (Noble Gas)
B K (Alkali Metal
C Ca (Transition Metal)
D Br(Halogen)
The correct answer and explanation is :
The correct answer is C) Ca (Transition Metal).
Explanation:
Calcium (Ca) is not a transition metal; rather, it belongs to Group 2 (Alkaline Earth Metals) of the periodic table. The transition metals are found in Groups 3-12, and calcium does not fall within this range.
Understanding Each Option:
- A) He (Noble Gas) – Correct
- Helium (He) is indeed a noble gas, located in Group 18 of the periodic table.
- It is colorless, odorless, and chemically inert under normal conditions, which are characteristic properties of noble gases.
- B) K (Alkali Metal) – Correct
- Potassium (K) belongs to Group 1, which consists of alkali metals.
- Alkali metals are highly reactive and form strong bases (alkalis) when combined with water.
- C) Ca (Transition Metal) – Incorrect
- Calcium (Ca) is an alkaline earth metal (Group 2), not a transition metal.
- Transition metals have partially filled d-orbitals, whereas calcium has a completely filled s-orbital in its valence shell.
- Calcium is highly reactive, commonly found in compounds like calcium carbonate (CaCO₃), and plays a critical role in biological functions like bone formation.
- D) Br (Halogen) – Correct
- Bromine (Br) is a halogen found in Group 17.
- Halogens are highly reactive nonmetals that readily form salts with metals.
Thus, the incorrectly labeled element is C) Ca (Transition Metal), since calcium is actually an alkaline earth metal.