2nd grade chemistry summary

The second and third periods are known as short periods. Each consists of eight elements. The second period starts with lithium (Z = 3) and ends with inert gas neon (Z = 10). The third period starts with sodium (Z = 11) and ends with argon (Z = 18..

Matter is anything that occupies space and has mass. Element is a pure substance, which can neither be decomposed nor built from simpler substances by any physical or chemical means. It contains only one kind of atom. Broadly speaking, elements can be divided into metals, non-metals and met..

Our body is made up of tissues, which are all composed of chemicals. We need an adequate supply of chemicals in the form of food, vitamins, hormones, and enzymes, which are in turn chemicals. For taking care of our health we need medicines. We find that chemicals and chemistry penetrate i..

>Mathematical statement of Boyles' law is P 1 V 1 = P 2 V 2 = constant. Charles' law states that pressure remaining constant, the volume of a given mass of a dry gas is directly proportional to the Absolute temperature. Mathematical statement of Charles' law is Absolute zero i.e..

Sulphur dioxide is found in volcanic gases and in the springs of volcanic regions. Its prepared by the direct combination of sulphur and oxygen or reaction of a metal with concentrated sulphuric acid. Sulphur dioxide acts as a bleaching agent only in the presence of moisture. The bleachi..

2 and MO type oxides. Their chemistry is characterized by (+2) oxidation state. In general, the heavier p-block elements favor low oxidation states. The most important element of group 15 is phosphorus. It exists in white, red and black allotropic forms. It forms ..

Troposphere is the blanket of air in which we live where all the weather is formed. Air is a mixture of 78.1% of nitrogen, 20.9% oxygen, 0.03 - 0.04% carbon dioxide, 0.94% noble gases and water vapour. Air is a mixture for the following reasons: - Air has a variable composition. - It has ..

Atoms are made up of three fundamental particles: electrons, protons and neutrons. Discharge tube experiments by William Crookes and J.J. Thomson led to the discovery of electron. Goldstein's experiment with the discharge tube having a perforated cathode led to the discovery of anode rays. ..

Carbon shows valencies 2 and 4, and forms two oxides - carbon monoxide (CO) and carbon dioxide (CO 2 )..

Carbon is the eleventh most abundant element in the earth's crust by mass. Carbon is the first member of group IVA and a typical non-metal. Carbon exhibits allotropy and shows maximum catenation. Carbon occurs both in free state as diamond, coal etc. and also in the combined form as CO h..