Astudent 600 ml cup of cocoa gets cold. it was only 25°c. he put it in the microwave. how many calories must transfer to the cocoa to bring it up to 70°c

To get the answer, you must know first the formula for heat.

Heat = mass X specific heat X change in temp 

We know that the mass is 600

Specific heat is 1

And the change in temperature is 70 – 25 which is 45.

Now plugging in those values:

Heat = 600 x 1 x 45 = 27,000 calories

Note: calorie is a unit of heat

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.

it's filtration, but this is an assumption so my apologies if i got this