Answer:
It is a physical change because this change is reversible and no chemical reaction occurs.
Explanation:
20.7 g of Fe can be produced with 10.0g of Al
So,
Formate has a resonating double bond.
In molecular orbital theory, the resonating electrons are actually delocalized and are shared between the two oxygens. So the carbon-oxygen bonds can be described as 1.5-bonds (option B). I'm not sure if option C is correct, however, because the likelihood of both delocalized electrons being in the area of one oxygen atom is less than 50%.<span />
Answer:
Uranium must be purified before it is used as a fuel source
Explanation:
The purer the uranium sample, the more the concentration of uranium in the fuel is.
Whenever uranium is extracted from nature, it contains a lot of impurities. Only a few special nuclear reactors can utilize uranium in this raw state. most of the others have to get uranium to become about 3% pure before they begin using it.
To do this, uranium has to be passed through a series of chemical reactions all with the aim of extracting the other compounds that may be present in the fuel.
Answer:
Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
Explanation:
Chemical change involves formation of new substances. Therefore, the correct answer is "Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form."