Question

give reason:
1. magnesium ribbon should be cleaned before burning in air.
2.photosynthesis is considered as an endothemic.
3.combustion reaction is an oxidation reaction

Answer 1

hey buddy..!!
1). magnesium ribbon should be cleaned before burning because...there will be a layer of oxide(mgo) in the ribbon...which will slow down the burning of the ribbon..

2) photosynthesis is considered as an endothermic reaction because...the process of photosynthesis needs energy from sunlight..so it is observing heat energy.. therefore this process is a endothermic reaction..

3) combustion reaction is a oxidation reaction because this reaction needs oxygen to burn...so it is an oxidation reaction...and it also forms oxides of the element burned...

HOPE THIS WOULD HELP U BUDDY!!!!
PLSS MAKE ME BRAINLIST!!!PLSSS!!

Answer 2

Magnesium ribbon must be cleaned before burning in air so that the layer of magnesium oxide (which is formed due to reaction of magnesium with air) can be removed in order to get the desired chemical reaction.