Animal charcoal differs from wood charcoal in that it

Analyze the question: We need a property that distinguishes animal charcoal (bone char) from wood charcoal.

Concept:

• Wood charcoal is made by heating wood in limited air. It is almost pure amorphous carbon.
• Animal charcoal (bone char) is made by heating bones in limited air. Bones contain a lot of calcium phosphate, so the product is only about 10% carbon, and the rest is mostly calcium phosphate (Ca₃(PO₄)₂).

Checking each option:

• A. Dark colour: Both are black or dark, so this is not a difference.
• B. High carbon content: Wood charcoal has the higher carbon content. Animal charcoal has a low one, so this is wrong.
• C. Good adsorbent: Both adsorb. Animal charcoal is used to decolourise sugar, and wood charcoal adsorbs gases and impurities. This is shared, not a difference.
• D. Crystalline: Both are amorphous forms of carbon, so this is wrong.
• E. Rich in phosphate content: Animal charcoal contains calcium phosphate from the bones, and wood charcoal has none. This is the real difference.

Answer: E. Animal charcoal is rich in phosphate (calcium phosphate), unlike wood charcoal, which is nearly pure carbon.

Tip: Think "bone = calcium phosphate." Whenever a question asks how animal charcoal differs from wood charcoal, look for the option that mentions phosphate or low carbon content.