On the whole, the metals burn in oxygen to form a simple metal oxide. Beryllium is reluctant to burn unless it is in the form of dust or powder. Beryllium has a very strong (but very thin) layer of beryllium oxide on its surface, and this prevents any new oxygen getting at the underlying beryllium to react with it.
All you need to do is to convert the velocity to meters per hour. Then multiply by 0.4 hours. I guess the answer was rounded up.
What following terms I don’t see any please make your question clear
Um u need to show what the options are.
