Over 6,458,000 live tutoring sessions served!

Top

Modern Physics 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 the terminals.

Certain heavy elements when they become unstable, they disintegrate giving out certain radiations - α,β particles and γ radiations.

All living things contain carbon and the amount of carbon 14 in them is enough to make them slightly radioactive.

Exposure to large amounts of radiation is harmful to health.

The nucleus of a radioactive substance spontaneously decays, giving off various kinds of radiations and getting transformed into the nucleus of another element.

Uranium and radium are two important naturally radioactive substances.

When a nucleus emits radiation it is said to decay.

Rays from radioactive isotopes are dangerous to living things but are also useful in variety of ways.

Exposure to large amounts of radiation is harmful to health.

All radioactive materials should always be handled with care and kept inside lead boxes.

An alpha decay causes the mass number to decrease by 4 and atomic number by 2.

Beta decay causes no change in the mass number, but the atomic number increases by 1.

Gamma emission has no effect on either the mass or atomic number.

Nuclear fission is the splitting of a heavy atom such as uranium into two lighter parts, accompanied with release of energy.

Words to Remember:-

Thermionic Emission, Cathode Rays, Radioactivity, Alpha Particles, Beta Particles, Gamma Rays, Carbon Dating, Background Radiation.

Related Questions

Related Calculators

Physical Pendulum Calculator