In chemistry, the study of rates and mechanisms of chemical processes and, of the factors on which they depend, is called kinetics. is the study of how fast chemical reactions occur. It provides evidence for the mechanisms of chemical reactions and studies the most effective way of causing a reaction to occur. It studies reaction mechanisms, examining what path the reactants take in order to become the products, and provides a very detailed picture of which bonds are broken and formed during the course of a reaction.

Correct Option: D

In chemistry, the study of rates and mechanisms of chemical processes and, of the factors on which they depend, is called kinetics. is the study of how fast chemical reactions occur. It provides evidence for the mechanisms of chemical reactions and studies the most effective way of causing a reaction to occur. It studies reaction mechanisms, examining what path the reactants take in order to become the products, and provides a very detailed picture of which bonds are broken and formed during the course of a reaction.

The nucleus is the small, dense region consisting of protons and neutrons at the center of an atom. Protons and neutrons are bound together to form a nucleus by the nuclear force. The atomic nucleus was discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.

Correct Option: A

The nucleus is the small, dense region consisting of protons and neutrons at the center of an atom. Protons and neutrons are bound together to form a nucleus by the nuclear force. The atomic nucleus was discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.

The plum pudding model, one of several scientific models of the atom, was first proposed by J. J. Thomson in 1904 soon after the discovery of the electron, but before the discovery of the atomic nucleus. In this model, atoms were known to consist of negatively charged electrons. The model represented an attempt to consolidate the known properties of atoms at the time.

Correct Option: B

The plum pudding model, one of several scientific models of the atom, was first proposed by J. J. Thomson in 1904 soon after the discovery of the electron, but before the discovery of the atomic nucleus. In this model, atoms were known to consist of negatively charged electrons. The model represented an attempt to consolidate the known properties of atoms at the time.

Soap solution is used to measure the hardness of rain water, temporarily hard water and sea-water. Hard water does not form soap lather. This is because magnesium ions or calcium ions present in hard water react with soap to form calcium stearate or magnesium stearate and thus forms scum.

Correct Option: C

Soap solution is used to measure the hardness of rain water, temporarily hard water and sea-water. Hard water does not form soap lather. This is because magnesium ions or calcium ions present in hard water react with soap to form calcium stearate or magnesium stearate and thus forms scum.

During an uncontrolled nuclear chain reaction such as atomic explosion, a radioactive substance gives off energy at a rate that increases rapidly with time, leading to large amounts of radiation and possibly an explosion. The radioactive decay of one atom triggers the decay of some of its neighbors, in turn setting off other atoms; thus, producing large amounts of energy.

Correct Option: D

During an uncontrolled nuclear chain reaction such as atomic explosion, a radioactive substance gives off energy at a rate that increases rapidly with time, leading to large amounts of radiation and possibly an explosion. The radioactive decay of one atom triggers the decay of some of its neighbors, in turn setting off other atoms; thus, producing large amounts of energy.