Shailesh Koirala 
The ionization energy depends upon the following factors: A) Size of the atom The ionization energy depends on the distance between the electron and the nucleus i.e., size of the atom. The attractive force between the electron and the nucleus is inversely proportional to the distance between them. Consequently, as the size of the atom … Read more
Mounting can be defined as the placing of the specimen or sample(e.g cheek cells) on a glass slide for microscopic observation. There are various ways of preparing mount. Some of them are as follows: A) Wet mount It is a common slide preparation method in the laboratory. This method is applied for instant observation of … Read more
Elemental oxygen exists as a triatomic molecule (O3) known as ozone in addition to di-oxygen. The existence of an element in more than one modification in the same physical state is referred to as allotropy. Ozone is an allotropic form of oxygen which is present in the upper atmosphere about 20 km above the surface … Read more
The orbital velocity of a satellite is the velocity required to be given to the satellite in order to put it in an orbit around the earth. Once the satellite is put in an orbit with required velocity, the satellite keeps on revolving around the earth. For the continuous revolution of the satellite around the … Read more
The force that acts at right angles to an imaginary line of unit length at the surface of liquid at rest is called surface tension. Simply, it can be defined as the force which is responsible for the tension at the surface of the liquid. It is one of the important properties exhibited by liquids … Read more
S.N Valve S.N Transistor 1. The charge carriers of valves are electrons. 1. The carriers of the transistors are the electron and holes. 2. In a valve the charge carries are provided by heater called hot cathode. 2. In a transistor, charge carriers are provided by emitter. No heater or heating elements are required. 3. … Read more
A) Diamagnetic Substances and its characteristics Diamagnetic substances are those substances which, in their normal states, have no magnetic moment at all. Antimony, Bismuth, Copper, Gold, Mercury, water, alcohol, Hydrogen are diamagnetic substances. Characteristics They are feebly repelled by magnet and magnetic field. When placed in a magnetic field, they all are weakly magnetized in … Read more
A) α-radiation The α-rays are not rays, but consist of a stream of positively charged particles, having 2 units of positive (+) charge, and 4 units of mass. Thus, α-particles are doubly ionized helium atoms i.e., He2+. The α-particles emitted by any radioactive source are shot out with high velocity. The initial velocity depends on … Read more
The air entering the pleural cavity is the reason of pneumothorax. Negative pressure that exists between the visceral pleura (surrounding the lungs) and the parietal pleura (lining the thoracic cavity) allows the lungs to be filled by chest wall expansion normally. The pleural space contains only a few millilitres of lubricating fluid that helps to … Read more
Sodium plays a major role being the main cation of extra-cellular fluid (ECF). It helps in maintaining the concentration and volume of extra-cellular fluid (ECF) and also influences the water distribution between ECF and intra-cellular fluid (ICF). It also helps in the generation and transmission of nerve impulses, muscle contractility and the regulation of acid-base … Read more