b) Riding a bike: your muscles using food energy from eating cookies
c) making popcorn
d) changing the colour of your hair
e) a light bulb turning on
f) a seed germinating
Please help... =)Which of the following are chemical or physical changes? and why?a) Chemical --- recharging I think requires redox reactions (i.e. chemical processes)
b) Chemical --- you derive chemical energy from food thus it is chemical change.
c) Physical - change of state from kernel to 'inverted' kernel
d) Chemical - pigments in dye react with the molecules of your hair.
e) Physical (maybe) - it changes from no letting light out and luminesing?
f) Chemical and physical - the seed changes shape caused by the biochemical reactions during germination.
Hope that helps!
