A student is trying to create a table that compares hypotheses, theories, and laws. Hypothesis
Theory
Law
Do scientific researchers formulate it?
Yes
Yes
Yes
Does it explain why things happen?
Yes
Yes
No

Yes
Yes
Yes
Is it used to make predictions?
No
Yes
Yes

Which of the following questions would most likely fill the blank in the table?
Is it an intelligent guess?
Is it newly formulated?
Is it based on observations?
Has it been proved?

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.