grade 8 physical properties of hydrogen

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 provocation ..

One of the most complicated optical devices is the human eye. Let us see the construction of the human eye and then the mechanism of image formation. Human eye is spherical in shape and diameter of about 2.5cm. Sclerotic is a tough, opaque and white substance forming the outermost coating..

Predict the effect on the electrical properties of a silicon crystal at room temperature (300 K) if every millionth silicon atom is replaced by an atom of indium. Given: concentration of atoms = 5 x 10 2 8 m - 3 ; intrinsic carrier concentration = 1.5 x 10 1 6 m - 3 ; ..

The thickness of the metallic rope needed to lift a given load is decided using the knowledge of elastic limit of the material of the rope and the factor of safety. Electric poles are made hollow A hollow shaft is found to be stronger than a solid one because the torque required to twist a hollow c..

Gauss's law for magnetism states that the net magnetic flux through any closed surface is zer..

Concentration of silicon atoms = 5 x 10 2 8 m - 3 Hole concentration is increased by the amount New electron concentration = 0.45 10 1 0 m - 3 Electron concentration is reduced by the amount Note that the electron concentration has decreased over its intrinsic c..

. where r , called resistivity is a property of the material and depends on temperature and pressure. Electrical resistivity of substances varies over a very wide range. Metals have low resistivity, in the range of 10 - 8 W m to 10 - 6 W m. Insulators like glass and rubber have ..

. (iii) Loss of one a - particle. decrease in mass number is 4 and decrease in atomic number is 2. Example 7:- Calculate the energy released when 1 kg mass is completely converted to energy (C = 3 x 10 8 m/s). Suggested Answer:- Example 8..

At NTP., with pressure of air = P = 0.76 x 9.8 x 13.6 x 10 3 = 1.013 x 10 5 Pa or Nm - 2 Substituting these values in equation (1-26) But this value of the velocity of sound at 0 o C, is not in agreement with the experimental value which is 332ms - ..

When a bar magnet is suspended freely, it always comes to rest in a north-south direction. This property is used in the construction of a mariner's compass. ..