Questions

In 1952, Waksman was awarded the Nobel Prize in Physiology or Medicine in recognition "for his discovery of streptomycin," the first antibiotic active against tuberculosis.

All enzymes are proteins but all proteins are not enzymes since, enzymes are subset of proteins.

Allotropes are different structural modifications of an element, that is, each of two or more different physical forms in which an element can exist.

Carbon is capable of forming many allotropes due to its valency. Well-known forms of carbon include charcoal, diamond, graphite, buckminsterfullerene and graphene.

Hence, Ethylene is not an allotrope of Carbon.

For neutral atoms, the periodic trends in atomic size can be described like this

Atomic size decreases when going from left to right across a period,
Atomic size increases when going from top to bottom down a group.

Let's use these trends to try and figure out which atom would have the largest radius.

If you look at elements that are located in the same group, potassium will have a larger atomic radius when compared with sodium. Likewise, bromine will have a larger atomic radius when compared with chlorine.

Now focus on potassium and bromine. Since potassium is located at the start of period 3, and bromine at the end of the same period, potassium will have a larger atomic radius than bromine, and thus the largest atomic radius of the four given atoms.

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms.

Abraham Lincolon was an American statesman and lawyer who served as the 16th President of the United States from March 1861 until his assassination in April 1865.

Lincoln led the United States through the American Civil War—its bloodiest war and perhaps its greatest moral, constitutional, and political crisis.