Question Discussion & Solution

The correct answer is carbon.

Key Points

• A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms.
  • The molecule may be a hollow sphere, ellipsoid, tube, or many other shapes and sizes.
• Various allotropes of carbon are diamond, graphite, lonsdaleite, fullerene, C-540, C-70, amorphous carbon, carbon nanotube.
• Diamond and crystalline silicon are isomorphous because they both have a three-dimensional tetrahedral structure.
• Allotropy, the existence of a chemical element in two or more forms, which may differ in the arrangement of atoms in crystalline solids or in the occurrence of molecules that contain different numbers of atoms.

Additional Information

• When an element exists in more than one crystalline form, those forms are called allotropes; the two most common allotropes of carbon are diamond and graphite.
  • One of the allotropic form of a carbon is a fullerene in which “carbon atoms” are “arranged in a sphere”.
  • Each sphere has 60 carbon atoms and each carbon atom is linked by a single covalent.
  • The fullerene is considered as purest allotrope of “carbon” because they have “smooth structure” without having dangling bonds.

The correct answer is Hygrometer.

Key Points

• Hygrometer
  • A hygrometer is an instrument for measuring the relative humidity of the atmosphere.
  • The hygrometer was invented by Leonardo da Vinci.

Additional Information

• ​Barometer
  • A barometer is an instrument used to measure atmospheric pressure.
  • The barometer was invented by Torricelli.
• Hydrometer
  • A hydrometer is an instrument used to measure the specific gravity of liquids.
  • The hydrometer was invented by Nicholson.
• ​Anemometer
  • An anemometer is an instrument used to measure the velocity of wind and directions.
  • The anemometer was invented by Leon Alberti.

Explanation:

Option 1 is correct, i.e. Anthracite.

• Anthracite, also called the hard coal is a highly metamorphosed form of coal.
• The calorific value of a substance is defined as the amount of heat released by a unit weight of a substance during complete combustion.
• Anthracite coal has the highest calorific value.

Anthracite is a type of coal that has the highest carbon content.

• Anthracite: 87-96%
• Bituminous: 45-86%
• Lignite: 25 - 35%

Extra information:​

• The most common volatile matter in coal is water, carbon dioxide, and sulfur dioxide.
•  Volatile matter is directly related to coal rank; as coal rank increases, volatile matter content decreases.
• Peat has the highest volatile matter.

It is not always necessary that we need a movie and an actor for a song. A song can be created without them. Microphone is also not essential for a song but lyrics are an essential part of a song as lyrics are the words that actually make up a song. Without, lyrics a song cannot be written.

The correct answer is Angiosperm.

Key Points

• Angiosperms are also known as Angiospermae or Magnoliophyta.
  • They are flowering and seed-producing plants.
  • It consists of 64 orders, 416 families, approximately 13,000 known genera, and 3,00,000 known species.
  • Their seeds develop in the ovaries of flowers and are surrounded by a protective fruit.
  • Examples of angiosperms are fruits, vegetables, grains, and flowers.
  • Angiosperms are classified as Monocotyledons (monocots) and Dicotyledons (dicots) where monocots are flowering plants whose seeds contain only one embryonic leaf or cotyledon and dicots are flowering plants whose seeds contain two embryonic leaves or cotyledons.

Additional Information

• Thallophyta
  • The plant body is not differentiated from roots, stems, and leaves.
  • They are commonly called algae.
• Bryophyta
  • These are small terrestrial plants.
  • They show differentiation in the body design, with stem, leaf-like structures, and root-like structures.