Katie's teacher has given her a sample that contains a mixture of salt, sand, and iron filings. She is
instructed to separate the mixture into the three individual components. What would be the best physical
property to focus on for the first step in separating the mixture?
a) Density
b) Electrical conductivity
c) Magnetism
d) Melting point

c

Explanation:

ljjjljlj kjlk,ljym jlyu; jm; l mumytj

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.