Questions

Antarctica is known as white continent because 98% of it's area is covered by ice throughout the year.

A manometer is used to measure a pressure difference between two points.

A Shrimps heart is located on its head.

A big bed of rock salt with the top portion of the bed containing potash (though not the variety used as ferilizer) has been discovered in Thar Desert at a depth of 100 metres. A massive belt of lead and zinc has been found in the Agucha area, while gold bearing rocks have been discovered in the Tuensang district of Nagaland.

The number of bonds between a pair of atoms is called the bond order.

Bond orders can be calculated from Lewis structures, which are the heart of the valence-bond model. Oxygen, for example, has a bond order of two.

When there is more than one Lewis structure for a molecule, the bond order is an average of these structures. The bond order in sulfur dioxide, for example, is 1.5  the average of an S-O single bond in one Lewis structure and an S=O double bond in the other.

In molecular orbital theory, we calculate bond orders by assuming that two electrons in a bonding molecular orbital contribute one net bond and that two electrons in an antibonding molecular orbital cancel the effect of one bond. We can calculate the bond order in the O₂ molecule by noting that there are eight valence electrons in bonding molecular orbitals and four valence electrons in antibonding molecular orbitals in the electron configuration of this molecule. Thus, the bond order is two.

First Generation  Vacuum Tubes (1940-1956)

The first computer systems used vacuum tubes for circuitry and magnetic drums for memory