Review Concepts

Magnet is a naturally occurring or artificially designed material which has a peculiar property of attracting some materials like iron, nickel and cobalt, called magnetic materials.

There are two types of charges: positive charge and negative charge. Like charges repel each other while opposite charges attract each other.

Light is the form of energy which makes the objects visible to us. When light reaches from object to our eyes, it becomes visible to us. Reflection, refraction and dispersion are the important properties of light.

Thermal energy, also called heat, is a form of energy which gives sensation of hotness. Like other forms of energy, its SI unit is Joule (J).

The product of displacement and force in the direction of displacement of a body is called work.

Gravity: The gravitational force due to earth is called gravity.

Inertia: The property of a body which tends to keep the body in its state of rest or of uniform motion is called inertia. Inertia is measure of mass.

A continuous change in the position of the object with respect to time is called motion.

Acids are the substances which taste sour, change blue litmus red, are corrosive to metals and furnish H+ ions in their aqueous solutions. Bases are the substances which taste bitter, change red litmus blue, feel slippery and furnish OH ions in their aqueous solutions.

The basic cause of chemical bonding is to attain noble gas configuration either by transfer of electron from a metal to non-metal or by sharing of electrons between two non-metal atoms. All the atoms have a tendency to acquire stable state or noble gas configuration and is called Octet Rule.

The first classification of elements was as metals and non-metals. After the discovery of atomic mass, it was thought to be the fundamental property of elements and attempts were made to correlate it to their other properties.

According to Dalton’s atomic theory, the atom is considered to be the smallest indivisible constituent of all matter. This theory could explain the law of conservation of mass, law of constant composition and law of multiple proportions.

A chemical equation is a shorthand description of a reaction. It symbolically represents the reactants, products and their physical states. In a balanced chemical equation, number of atoms of each type involved in the chemical reaction is equal on the reactants and products sides of the equation.

According to law of constant proportions, a sample of a pure substance always consists of the same elements combined in the same proportion by mass.

Anything that has mass and occupies space is matter. There are three different physical states of matter - solid, liquid and gas. A particular state of matter can be changed into other states by changing the temperature or pressure.

Measurement is a process of comparing a physical quantity with a standard quantity. The standard quantity used to compare a physical quantity for its measurement is called unit. The internationally accepted modern system of units used in science is known as SI units.

Probability is that branch of Mathematics which deals with the measure of uncertainty in various phenomenon that gives several results or outcomes instead of a particular one.

Statistics is a branch of Mathematics which deals with collection, presentation, analysis, interpretation of data and drawing of inferences or conclusions there from.

Trigonometry is that branch of Mathematics which deals with the measurement of the sides and the angles of a triangle and the problems related to angles. Ratios of the sides of a triangle with respect to its acute angles are called trigonometric ratios.

Solid figures include cube, cuboid, cylinder, cone, sphere, and hemisphere.