The answer is A, a new chemical substance has to be formed for there to be a chemical change. This is because chemical change happens when a phase of matter changes due to chemicals.
Answer:
No. 4
Explanation:
Bacteria are produced from pre existing bacteria
Answer:
The correct answer is option D, that is, magic numbers.
Explanation:
The magic number in nuclear physics refers to the number of nucleons, that is, either neutrons or protons, distinctly, such that their alignment results in the formation of complete shells within the nucleus of the atom. As a consequence, atomic nuclei comprising a magic number of neutrons or protons are much more stable in comparison to other nuclei.
The seven most broadly known magic numbers are 2,8,20,28,50,85 and 126.
Answer:
The percent yield of the reaction is 82.5%
Explanation:
Let's work with moles to get the percent yield.
Mass / Molar mass =
652.5 g / 158.03 g/m = 4.13 moles
If the theoretical yield of the reaction is 5 moles but we only made 4.13 moles, the percent yield will be:
(Produced yield / Theoretical yield) . 100 =
(4.13 / 5) . 100 = 82.5 %