Questions

In this chemical reaction chlorine change oxidation number from 0 to -1 (reduction) and bromine change oxidation number from -1 to 0 (oxidation).

Chlorine is stronger oxidation reagent than bromine.

In VIIA or group 17 (halogen elements) there are six elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At) and tennessin(Ts).

They have high electronegativity because they have seven valence electrons in their outermost energy level, so they can gain an electron to have the octet rule.  

Going down in the group, element are weaker oxidazing reagent and less reactive.

The Highest bridge in the world is Bailey bridge. It is located in the Ladakh valley between Dras and Suru rivers in the Himalayan mountains. It was built by the Indian Army in August 1982.

It is 30 meters (98 ft) long and is at an altitude of 5,602 meters (18,379 ft) above sea level.

Most operating systems store files on a hard disk.

The first indicator of an approaching thunderstorm is a buildup of dark clouds.

A thunderstorm is a storm with lightning and thunder; it is usually produced by heavy rain, gusty wind, and the cumulonimbus cloud. The thunderstorm is made up of moisture, unstable air and lift.