Question

which of the following are chemical changes-
respiration of animals
burning of coal
rusting of iron
digestion
or is it
all of the above
plzz helppp

Answer 1

rpelyy
plzzzzz

Answer 2

@Somy @veronica.montanez

Answer 3

http://chemistry.about.com/od/matter/a/10-Chemical-Change-Examples.htm

Answer 4

respiration of animals - glucose breaks down to form energy CO2 and H2O
burning of coal - burns thus meaning we will have a different product
rusting of iron- its burning of Fe - again something changes in properties of the final compound
digestion- break down of large molecules to small ones

Answer 5

these all are chemical changes

Answer 6

thnxxxx

Answer 7

http://chemistry.about.com/od/matter/a/Examples-Of-Physical-Changes-And-Chemical-Changes.htm
check this out to get the idea about chemical and physical changes
np :)