Answer: True
Air is a mixture of many things; it's not just Oxygen, but Hydrogen, Carbon, and Nitrogen as well are made up of air. Fun fact: Nitrogen is actually more abundant in air
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.
Answer:
The right answer is "3 g".
Explanation:
Given:
Initial mass substance,
By using the relation between half lives and amount of substances will be:
⇒ 
Thus, the above is the correct answer.
