In 1820, Danish physicist Hans Christian Oersted found that a current running through a wire created a magnetic field, kicking off the modern study of electromagnetism.
Moving electric charges create magnetic fields. You can test this by placing a compass near a current-carrying wire. The compass will line up with the induced magnetic field.
To determine the direction of the electrically-induced magnetic field due to a long straight current-carrying wire, use the first right hand rule (RHR) by pointing your right-hand thumb in the direction of positive current flow. The curve of your fingers then shows the direction of the magnetic field around a wire (depicted at right).
You can obtain an even stronger magnetic field by wrapping a coil of wire in a series of loops known as a solenoid and flowing current through the wire. This is known as an electromagnet. You can make the magnetic field from the electromagnet even stronger by placing a piece of iron inside the coils of wire. The second right hand rule tells you the direction of the magnetic field due to an electromagnet. Wrap your fingers around the solenoid in the direction of positive current flow. Your thumb will point toward the north end of the induced magnetic field, as shown below.
Exothermic reactions increase the entropy of the surroundings. Simply put, entropy measures the dispersal of energy. Since ΔH is negative in an exothermic reaction, this must mean that ΔS will take on a positive value, indicating an increase in entropy.
Potassium Chloride is an ionic compound and has ionic bond which is stronger than covalent bond in ethyl alcohol,water ,ammonia, and thus has the highest boiling point .
ionic bond is a type of bond that results from the transfer of electrons between metallic atoms and non-metallic atoms.
