Molybdenite, which appears as a soft, lead grey mineral, is an important ore of which metal?

Introduction / Context:
Ores and minerals form a key part of both chemistry and geography syllabi. Each important metal is associated with a few characteristic ores that students are expected to recognise. Molybdenite is one such mineral whose name hints at its relationship with the metal molybdenum. This question checks whether you can correctly link molybdenite with the right metal from a short list that includes several other common metals.

Given Data / Assumptions:
- The mineral named in the question is molybdenite.
- Four metals are provided as options: molybdenum, nickel, silver, and tin.
- The question asks which metal has molybdenite as an ore or important mineral source.
- Standard high school or introductory college level mineralogy information is assumed.

Concept / Approach:
Molybdenite is a naturally occurring molybdenum disulphide mineral, often written as MoS2. It resembles graphite in appearance and feel but contains molybdenum instead of carbon. Molybdenum metal is extracted primarily from molybdenite and from some copper ores that contain molybdenum as a by product. Nickel, silver, and tin each have their own characteristic ore minerals, such as pentlandite for nickel, argentite for silver, and cassiterite for tin. They are not mainly obtained from molybdenite. Therefore, the correct association is between molybdenite and molybdenum.

Step-by-Step Solution:
Step 1: Recall that molybdenite has the formula MoS2 and is structurally similar to graphite, but with molybdenum atoms present. Step 2: Recognise that Mo stands for molybdenum in the periodic table, so the mineral clearly contains molybdenum. Step 3: Understand that molybdenum is extracted from molybdenite by roasting and subsequent processing. Step 4: Consider nickel, silver, and tin. Their key ores are pentlandite and other sulphides for nickel, argentite and related minerals for silver, and cassiterite for tin. Step 5: Conclude that molybdenum is the metal for which molybdenite is a principal ore.

Verification / Alternative check:
If you consult a table of important ores in a chemistry textbook, molybdenite is almost always listed under molybdenum ores. The entry typically describes it as molybdenum disulphide and explains its use in producing molybdenum metal and lubricants. The same tables do not list molybdenite as an ore of nickel, silver, or tin. Instead, they associate those metals with different minerals. This cross check with standard references verifies that molybdenum is the correct answer.

Why Other Options Are Wrong:
Nickel: Commonly obtained from pentlandite, nickeliferous laterites, and other ores, not from molybdenite.
Silver: Extracted mainly from argentite and other silver bearing minerals, not from molybdenite which contains molybdenum and sulphur.
Tin: Produced from cassiterite, a tin oxide ore, rather than from molybdenite.

Common Pitfalls:
Because molybdenite looks somewhat like graphite, some learners may recall its physical appearance but not its composition, leading to confusion about the associated metal. Another pitfall is to ignore the hint provided by the name itself, which shares the root molyb with molybdenum. Remembering that many ore names contain parts of the element name, such as bauxite for aluminium and hematite for iron in some languages, can make these associations easier to learn and recall during exams.

Final Answer:
Molybdenite is an important ore of Molybdenum, from which molybdenum metal is extracted for use in alloys and industrial applications.