Questions

An atom is the smallest particle of a substance. Chemical substances are divided into two major groups. They are

1. Pure Substances (and)

2. Mixtures.

There are two types of pure substances that are Elements and Compounds.

Elements : An element is a substance that is made up of only one kind of atoms and cannot be broken down into simpler substances by chemical means. Metals and Non- metals come under elements.

Examples of elements are Iron, Silver, Gold, Mercury etc.

Compounds : A Compound is a substance that is formed when two or more elements combine chemically.

Examples of compounds are Water, Carbon dioxide, methane, vinegar etc.

Mixtures : A Mixture is formed when two or more substances mixed together but not chemically combined.

Example: Air.

Bond order is proportional to the bond length is a False statement since Bond order is inversely proportional to the bond length.

Secondary succession means in an ecosystem renewal of itself after all or a portion has been destroyed.

After a forest fire, the whole forest had destroyed but after that again renewal of that forest is also an example of secondary succession.

The strength of an electromagnet can be increased by increasing the cross-sectional area, increasing the number of turns, increasing current supply, increasing the length of the coiled wire.

Cobalt therapy or cobalt-60 therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer.

Cobalt 60 is a synthetic radioactive isotope of cobalt with a half-life of 5.2714 years. It is produced artificially in nuclear reactors.

A large underground economy results in an Overstated GDP. The underground economy is also called as Black market. It refers to illegal economic activity. Transactions in the underground economy are illegal either because the good or service being traded is illegal or because an otherwise licit transaction does not comply with government reporting requirements.

Shahi Litchi of Bihar recently got a GI tag and got official recognition for Muzaffarpur in Bihar.