Laura is separating a mixture of sand and water by decanting. She lets the sand all settle to the bottom of the container and then slowly pours the water into a new, clean container. This leaves all the sand behind in the bottom of first container
Why is decanting an effective method of separation for water and sand?
OA. Water and sand have similar properties.
ОВ.
Water and sand have different densities.
OC.
Water and sand are both pure substances
OD
Water and sand have different colors.

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.

why is arctic sea ice important? arctic sea ice keeps the polar regions cool and moderate global climate. sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space. as sea ice melts in the summer, it exposes the dark ocean surface.