Because things that are burnt have been changed into something else like moldy bread thats cooked.
It is chemical change because you cannot unburn something.
Try googleing it that is how i got some of mine
A contains 38.5 g of tin for each 12.3 g of fluorine:
<span>mole ratio: </span>
<span>(38.5 g)/(118.71 g/mol):(12.3 g)/(18.998 g/mol) = 0.324:0.647 = 1:2 ⇒ SnF₂ </span>
<span>B contains 56.5 g of tin for each 36.2 g of fluorine: </span>
<span>mole ratio: </span>
<span>(56.5 g)/(118.71 g/mol):(36.2 g)/(18.998 g/mol) = 0.476:1.905 = 1:4 ⇒ SnF₄
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
</span>
The motion of molecules in a ice cube are so packed together that they can't move freely like molecules in liquids and gases
