Isotopes are variants of a particular chemical element which differ in neutron number, although all isotopes of a given element have the same number of protons in each atom. The term isotope is formed from the Greek roots isos and topos, meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table.
Surface tension in water owes to the fact that water molecules attract one another, as each molecule forms a bond with the ones in its vicinity. ... This inward net force causes the molecules on the surface to contract and to resist being stretched or broken.
The best answer is (1)
Fossil fuels are commercially available as an energy source.
They are very easy to find. More and more extractions of fossil fuels is going on everyday. With advancement in science and technology, the refineries and extraction procedures have improved a lot. This makes their availability even better.
Fossil fuels are also easily combustible. Most combustion engines need to be powered with little amount of fuel to produce large amount of energy. Very large amounts of electricity can be generated from fossil fuels.
I got D, C, A, B, C, B, D, C.
C (proteins) instead of D (nucleic acids) because if you look at a nucleic acid structure, you'll see that sulfur is not found in it. Sulfur is found in two amino acids (methionine and cysteine), which means it could be found in proteins since amino acids build proteins
