Define Radioactivity

Content Curator

Radioactivity is the act of emitting radiation spontaneously. Radioactivity occurs through an atomic nucleus that is unstable. It "wants" to give up some energy to shift to a more stable configuration.

In Physics. Radioactivity is a nuclear phenomenon of spontaneous emission of α (Alpha) or β (Beta) or γ (Gamma) radiations from the nucleus of atoms during their decay. Uranium and Plutonium exhibit radioactivity and are examples of a radioactive substance.

Radioactivity

Radioactivity

Also read:

Important Study Guides
Class 12 Physics Notes	Difference between in physics	Physics Constants
Physics Practical	SI Units in Physics	Physics Formula
Derivations in Physics	Relation Between articles (Physics)	Physics

CBSE CLASS XII Related Questions

1.
Read the following paragraph and answer the questions that follow.
In an experiment with convex lens of focal length f, the screen is fixed at a distance D from the object. A student slowly moves the lens away from the object towards the screen and finds that she is able to form sharp image of the object for two positions of the lens. The distance between these two positions of the lens is d.
2.
Capacitors are manufactured with certain standard capacitances and working voltages. However, these standard values may not be the ones that are actually needed in a particular application. Two or more capacitors can be grouped in series or in parallel to achieve desired capacitance and voltage. When connected in series, the total capacitance decreases while the voltage rating increases, whereas in parallel connections, the total capacitance increases and maintains the same voltage rating. A capacitor stores energy in the electric field between its plates and stored energy is proportional to the square of the voltage and capacitance $U = \frac{1}{2}CV^2$, where symbols have their usual meanings.
Two capacitors, one of $3 \ \mu$F and the other of $6 \ \mu$F, are connected in series in the circuit as shown in the figure, for a long time. }
3.
Two air-filled capacitors of capacitances $C_1$ and $C_2$ are connected in parallel with a dc battery. After the capacitors are fully charged, a slab of dielectric constant K is inserted between the plates of each capacitor. How will the (i) charge on each capacitor and (ii) energy stored in the capacitor affected after the slab is introduced.
View Solution
4.
Write two advantages of reflecting telescope over refracting telescope.
View Solution
5.
This ‘average velocity’ is found be few mm/s for currents in range of a few amperes. How then is current established almost the instant a circuit is closed ?
View Solution
6.
An astronomical telescope consists of two converging lenses. One of them of large aperture and large focal length is called objective lens and the other one, of smaller focal length and smaller aperture is called the eyepiece. It is used to see distant objects which are not seen clearly with naked eyes. The image formed by the objective lens acts as an object for the eyepiece and the final image produced by the eyepiece is magnified.