In the bookstore Avanti gave four books so it would be 1
Answer:
<em>The correct option is B) two liquids are mixed at room temperature and a gas forms.</em>
Explanation:
A chemical change can be described as a change which results in the formation of a new substance by the reactants. In the option B, two liquids react to form a new product which is a gas. Hence, it is an example of chemical change.
Other options,like option D, is not a chemical change as by crushing a solid no new product is formed. Option C is also not correct because as when salt dissolves in water, no new product is made.
Answer:
atoms of 40K
Explanation:
You can use the molecular mass and the Avogadro´s number, in the following formula:
where 
is the sample mass, 
is the molecular mass of the KCl and IA(40K) is the isotopic abundance of 40K.
Now replacing the values, you can find:
A standardized test of what you want to do with your friends and you get to know what you think you want to be tre
