In the modern periodic table, which of the following elements are classified as metalloids because they show properties intermediate between metals and non metals?

Introduction / Context:
Metalloids are elements that show a mixture of metallic and non metallic properties. They are very important in chemistry and materials science because they often act as semiconductors and are widely used in electronics and alloy design. Competitive exams frequently ask students to identify which elements are metalloids from a given list, so knowing the standard examples is a useful memory point for general knowledge and periodic table questions.

Given Data / Assumptions:

• The options mention three elements: arsenic, boron and antimony.
• We are working with the standard long form periodic table used in school and college chemistry.
• Metalloids are those elements that are normally placed along the diagonal zigzag line that separates most metals from non metals.
• We assume standard chemical behaviour at ordinary temperature and pressure.

Concept / Approach:
Metalloids have physical and chemical properties that are intermediate between typical metals and typical non metals. They may be shiny like metals but brittle like non metals, and many of them are semiconductors rather than good conductors. In the periodic table, classic metalloids include boron, silicon, germanium, arsenic, antimony and tellurium. Because the question lists arsenic, boron and antimony, all three of which are on that standard metalloid list, the correct response must recognise that every element mentioned is a metalloid rather than only one or two of them.

Step-by-Step Solution:
Step 1: Recall the commonly accepted metalloids: boron, silicon, germanium, arsenic, antimony and tellurium. Step 2: Check each option element against this list. Boron appears near the top of the zigzag line and is a classic metalloid. Step 3: Arsenic lies in group 15 in the metalloid region of the periodic table and shows both metallic and non metallic behaviour. Step 4: Antimony lies below arsenic, is shiny but brittle, and is also classified as a metalloid. Step 5: Since all three named elements are metalloids, the correct choice must be the option that says all of the above.

Verification / Alternative check:
Textbooks and periodic table charts often shade metalloids differently from metals and non metals. If you look at such a diagram, you will see boron at the top of the metalloid staircase, arsenic in the middle and antimony below it, all labelled as semimetals or metalloids. Their actual uses support this classification: boron is used in special glasses, arsenic in certain semiconductor applications, and antimony in alloys and flame retardants. None of them behaves like a typical alkali metal or a typical halogen, which confirms that they belong to this intermediate category.

Why Other Options Are Wrong:
- Arsenic alone: This ignores the fact that boron and antimony are also standard metalloids, so it is incomplete.
- Boron alone: Again, this recognises only one metalloid and wrongly excludes the others.
- Antimony alone: This option treats antimony as special but leaves out arsenic and boron, which is incorrect.
- None of the above: This would imply that none of the listed elements are metalloids, which directly contradicts periodic table classifications.

Common Pitfalls:
Students sometimes memorise only two or three metalloids and forget the full list. Another common confusion is between metalloids and transition metals, or between metalloids and typical non metals like phosphorus and sulphur. A useful memory trick is to see the zigzag line on the periodic table and remember that the elements sitting exactly on that line, such as boron, silicon, arsenic and antimony, are usually the metalloids. This mental image helps when answering quick multiple choice questions under exam pressure.

Final Answer:
All of the listed elements are metalloids, so the correct choice is All of the above.