physical properties and chemical properties of lead

Electrons in different metals can have different energies. If two of these metals are placed in a conducting liquid (electrolyte) a difference in electrical potential is set up between them. A pair of different metals arranged in this way is an electrochemical cell. It converts chemical e..

X-Rays follow a rectilinear propagation and travel with a velocity of 3 x 10 8 ms - 1 in vacuum. They are not deflected by electric and magnetic field. Since they do not contain any charge but are diffracted by crystals, X-rays cause fluorescence when incident on certain materials such as barium..

Nuclear energy is released when very small particles of matter split or combine. After the split or combination, they result in small particles or heavy particle. The rest of the mass is changed into energy. This process of changing mass into energy produces the energy. Energy can also be stored ..

We heat raw food to soften it. We freeze water into ice by cooling it in refrigerator. When we boil water in a kettle we observe the steam oozing from the mouth of the kettle. When the cork is difficult to remove, we slightly heat the mouth of the bottle, so that the cork comes out easily. Through ..

External forces acting on a body, bring about a change in its state or configuration. The latter is possible when the body is not free to move, but the molecules are compelled to change their positions. Such forces are called deforming forces. These forces bring about a change in the length, volume..

The number of protons or the number of electrons in an atom in its normal state is called the atomic number and is denoted by Z. The nucleus of every element contains Z protons and some number of neutrons. The electrons, having the same charge as a proton but of opposite sign, nullify the charge of..

Isotopes of an element have same atomic number (Z) but different mass numbers (A). For example, 1 H 1 , 1 H 2 , 1 H 3 are isotopes of hydrogen;..

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 and is a pr..

This theory explains the physical properties of matter in terms of motion of its molecules. According to this theory, every substance (solid, liquid or gas) consists of a large number of minute particles called molecules . A molecule may be defined as the smallest particle of a ..

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..