Questions

Vapour of carbon tetra chloride ccl4 is non-inflammable and is heavier than air. Hence it is used as a fire extinguisher under the trade name of pyrene.

Among the given options Brass is not a compound. Since it is an alloy, it is a mixture. It is a mixture of copper and zinc.

The smallest part of a compound is called a molecule. It has a unique composition that is always the same.

Compound is a substance that consists of two or more elements. 

Sri Ramakrishna is called as the Prophet of New India.

Sri Ramakrishna (1836-86) mostly known as Ramakrishna Paramhamsa was a spiritual genius now respected in India and abroad as an outstanding saint of our times. His life and thoughts represents the highest and best of modern Hindu philosophy and practice.

Reverence and admiration for him amongst Bengali elites led to the formation of the Ramakrishna Mission by his chief disciple Swami Vivekananda. His devotees look upon him as an incarnation or Avatara of the formless Supreme Brahman as described in the Vedanta while some devotees see him as an avatara of Vishnu.

Excretion is best described as the removal of Metabolic wastes from a cell.

 It can be possible in only B.C. i.e, Before Christ. That was about 2000 years ago.

 Given, 

 In 1990 B.C = 2000 + 1990 = 3990 years ago, a person is 15 years Old  

=> In 1995 B.C = 2000 + 1995 = 3995 years ago, the same person will be 10 years Old 

Therefore, In 2000 B.C = 2000 + 2000 = 4000 years ago, the same person will be 5 years Old.