Answer is: because they were using simple chemical reactions to transform elements, but that is possible only with nuclear reactions, which in that time were not possible to conduct.
Nuclear reactions can produce new elements, because number of protons and neutrons is changed, lead and gold have different atomic and mass numbers.
The electrons of an atom participates in a chemical reaction, chemical reactions involve the rearrangement of electrons, because there is transfer, loss, gain and sharing of electrons in chemical reactions, new elements are not formed.
A Cell with few energy needs would most likely contain a small number of Mitochondria.
- All cells require energy to function, but cells typically have significant energy needs that can only be met by the mitochondria, the cell's powerhouse.
- They transform glucose into ATP, a chemical with a huge energy storage capacity.
- Muscles have a large number of mitochondria, allowing them to react rapidly and powerfully to the body's ongoing need for energy.
- Macromolecules, defunct cell components, and microbes are all digested by lysosomes.
- Vacuoles are typically tiny and aid in the sequestration of waste.
- The ribosome, an intercellular structure consisting of both RNA and protein, is where a cell produces new proteins.
Therefore out of all these cell organelles, the cell has fewer mitochondria for less energy need.
Learn more about cell organelles here:
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30% should be the percentage of oxygen if the total mass of fe2o3 is 160.
Answer:- B. 4.65 g.
Solution:- The given balanced equation is:
It asks to calculate the mass of silver sulfide formed by when 0.0150 liters of 2.50 M of silver nitrate are used.
Moles of silver nitrate are calculated on multiplying it's liters by its molarity and then on multiplying by mol ratio, the moles of silver sulfide are calculated. These moles are multiplied by the molar mass to convert to the grams.
Molar mass of 
= 2(107.87)+32.06 = 247.8 g per mol
The dimensional set up for the complete problem is:
= 
So, the correct choice is B. 4.65 g.
