The answer is (D) microscopic. You can remember this, because the name is very close to "microscope," an instrument used to greatly magnify and observe tiny organisms and objects.
Explanation:
According to law of conservation of mass, mass of the reactants is equal to the mass of products in a chemical equation. As mass can neither be created nor it can be destroyed but it can be transformed from one form to another.
As it is given that hydrogen and in excess oxygen is reacting that leads to the formation of water. Hence, the chemical reaction equation will be as follows.
Since, it is given that 4 mol of hydrogen is reacting with excess of oxygen and gives 2 moles of water.
Hence, number of moles of water produced is calculated as follows.
4 mol of 
= 4 moles of 
Thus, we can conclude that 4 moles of water you can produce from 4.0 mol of hydrogen and excess oxygen.
Hi there!
Although there are only 20 amino acids, these amino acids can combine into an innumerable amount of combinations to form different and unique proteins.
In case that doesn't make sense to you, I'll provide you with an analogy. You could be provided with 20 different LEGO bricks to work with. While there may only be 20 bricks, these bricks can combine into a vast amount of different formations, structures, etc. Amino Acids work in the same way.
2n² rule:
This rule is used to determine number of electrons in particular shell.
n=1 means K shell
n=2 means L shell
n=3 means M shell
n=4means N shell
The first K shell can hold upto 2 electrons, L shell can hold up to 8, third M shell can hold up to 18and the fourth N shell can hold upto 32 electrons. This rule of arrangement of electrons according to the shell is known 2n2 rule where n means number of shell.
For example: There is one proton in the nucleus of hydrogen atom, which moves in K shell path. It has no neutron.
Answer:
to show that atoms are conserved in chemical reactions
Explanation:
