Which one of the following does not happen during a chemical reaction?
Breaking of old chemical bonds and formation of new chemical bonds
Formation of a new substance with entirely different properties
Atoms of one element change into those of another element to form new products
Rearrangement of atoms takes place to form a new product

No new substance is formed during a chemical reaction………..

State which of the following pertain to - chemical changes. No new substance is formed.

One or more new substances are formed in a chemical change.

State which of the following pertain to - chemical changes. Produces one or more new substances by change in its composition.

Name the type of chemical bond formed by a complete transfer of electrons from the valence shell of one atom to the valence shell of another atom.

Chemical reaction in which two elements combine to form a new compound is known as a …………….. Reactions.

Name the following. The gaseous product of the chemical change which takes place during respiration in living organisms.

Which one of the following roles is not characteristic of an essential element? 1. Being a component of biomolecules. 2. Changing the chemistry of soil. 3. Being a structural component of energy related chemical compounds. 4. Activation or inhibition of enzymes.

Which of the following are incorrect statements? (a)Crossing over during fusion of gametes result in formation of new combination of characters. (b)Natural selection can lead to change in allelic frequencies. (c) According to Lamarck, use and disuse of organs is major driving force behind evolution of life forms. (d)increase in number of heterozygotes[HbA/Hbs]over homozygotes[HbA/HbA or Hbs/Hbs] in malaria prone area is an example of directional selection.

Different types of bond are formed in the chemical compound. These bond have different strength and bond energies associated with them. These bond are formed with atoms in different environments. Which of the following bond has highest bond energy ?