Questions

Tuberculosis (TB) was the leading cause of death in the United States and one of the most feared diseases in the world during the 19th and early 20th centuries.

Formerly known as Consumption diseases because many types of lung diseases were lumped under the term 'consumption'. Lung cancer and bronchitis were examples.

A number of possible explanations for why manhole covers are round include :

1. A round manhole cover cannot fall through its circular opening, whereas a square, rectangular, or oval manhole cover could fall in if it were inserted diagonally in the hole.

2. Circular covers don’t need to be rotated or precisely aligned when placing them on the opening.

3. A round manhole cover is easily moved and rolled.

4. Human beings have a roughly circular cross-section.

5. Round tubes are the strongest shape against the compression of the earth around them, so the cover of the tube would naturally be round as well.

6. It’s easier to dig a circular hole.

The Chambal's lower course is lined by belt of badland gullies resulting from accelerated soil erosion and is the site of a major projectin soil conservation.Chambal Project is a joint project from both Madhya Pradesh and Rajasthan government, which aims at harvesting the Chambal River for irrigation, power prevention and control of soil erosion in the valley

Molecular compounds are those with covalent bonds between the elements and those elements are typically non metals.

Here in the given options, Ar is an element. NaI has an ionic bond. Hence, N2O4 has a covalent bond between the two non metals and is a molecular compound.