Questions

Only H and Br form Polar Covalent Bond.

Covalent bonding:

Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability, which is gained by forming a full electron shell. By sharing their outer most (valence) electrons, atoms can fill up their outer electron shell and gain stability.

1. Polar Covalent Bond

2. Nonpolar Covalent Bond

1. Polar Covalent Bond:

A Polar Covalent Bond is created when the shared electrons between atoms are not equally shared. This occurs when one atom has a higher electronegativity than the atom it is sharing with. The atom with the higher electronegativity will have a stronger pull for electrons (Similiar to a Tug-O-War game, whoever is stronger usually wins). As a result, the shared electrons will be closer to the atom with the higher electronegativity, making it unequally shared.

2. Nonpolar Covalent Bond:

A Nonpolar Covalent Bond is created when atoms share their electrons equally. This usually occurs when two atoms have similar or the same electron affinity. The closer the values of their electron affinity, the stronger the attraction. This occurs in gas molecules; also known as diatomic elements. Nonpolar covalent bonds have a similar concept as polar covalent bonds; the atom with the higher electronegativity will draw away the electron from the weaker one.

Here H and H and N and N form Non-polar covalent bonds. Na and Br form the ionic bond.

J.M Keynes’ theory of employment is a demand-deficient theory. This means that Keynes visualised employment from the demand side of the model. His theory is a demand-oriented approach, as opposed to the classical supply side model.

According to him,the volume of employment in a country depends on the level of effective demand of people for goods and services. Thus, unemployment is attributed to the deficiency of effective demand.

The Olive ridley turtles are the smallest and most abundant of all sea turtles found in the world, inhabiting warm waters of the Pacific, Atlantic and Indian oceans. These turtles, along with their cousin the Kemps ridley turtle, are best known for their unique mass nesting called Arribada, where thousands of females come together on the same beach to lay eggs. Though found in abundance, their numbers have been declining over the past few years, and the species is recognized as Vulnerable by the IUCN Red list.The coast of Orissa in India is the largest mass nesting site for the Olive-ridley, followed by the coasts of Mexico and Costa Rica.

“To aid” means to give financial or material help. So, option 2 is the best-fit answer. Amplify- increase

When the piece of iron is lowered into the water, the water level in the bucket increases. And so the pressure at the bottom of bucket also increases. Thus the total thrust at the botto also increases. Therefore the spring balance reading increases.