gamma radiations

In 1899, the study of radioactivity was taken up by Ernest Rutherford. He placed a little radium at the bottom of a small lead box and subjected the rays that emerged from it to the action of a very strong magnetic field at right angles to their direction. He found that the rays separated into thr..

Radioactive nuclei being unstable, emit radiations to achieve states of greater stabilit..

>Three types of radiation from recognized radioactive elements are a -particles, b -particles and g -radiation. It was realized that radioactivity of an element is independent of its physical state, its chemical environment or temperature, suggesting that it is a property of the..

Protons and neutrons Nuclear forces Electromagnetic repulsion between the protons Nuclear fusion and fission reactions Radioactive isotopes Three most common forms of radioactive decay (alpha, beta, gamma) Changes in the nucleus in each type of decay Alpha, beta, and gam..

Protons and neutrons Nuclear forces Electromagnetic repulsion between the protons Nuclear fusion and fission reactions Radioactive isotopes Three most common forms of radioactive decay (alpha, beta, gamma) Changes in the nucleus in each type of decay Alpha, beta, and gam..

(i) Radioactive dating This gives us an approximate age of the rock or material containing the radioactive atoms. For e.g., A measurement of a fraction of uranium atom which have decayed into lead (by knowing the half life of uranium) tells us how old the rock is. (ii) Radiation from s..

It is a nuclear phenomenon. It is due to the instability of the nucleus. It is a spontaneous, continuous and irreversible process. It is independent of external factors such as pressure, temperature, state of substance, electrical field, magnetic field, catalyst etc. A radioactive ele..

Above the troposphere is the stratosphere. This zone is rich in ozone. Hence, it is also called ozonosphere. In ozonosphere, oxygen in the presence of sunlight converts to ozone by photochemical dissolution. The ozonosphere completely absorbs short wave solar radiations, such as ultravio..

Radioactivity - It is a spontaneous emission or disintegration of an unstable nucleus resulting in certain radiations. The elements exhibiting this phenomena are called radioactive elements. e.g., radium, thorium, actinium, polonium etc. Radioactivity does not occur due to any external pr..

Summary - When certain metals are heated to a high temperature, they emit thermions (electrons) and the phenomenon is called thermionic emission Cathode rays are a stream of negatively charged particles emitted from the cathode of an evacuated bulb, when a voltage of nearly 3000 volts given across ..