A cut.
No but it can get infected.
Yes; it probably will. I am sorry.
knock it down
it hurts and puss comes out
If you burn infected files onto an optical disc then those files remain infected and would remain on the optical disc permanently.
They burn chimicals to protect molecules from getting infected by energy.
Yes, that is why they store infected grain and then burn them.
Ask the doctor.
no, it is not. It will sting a bit, of course, but won't harm you.
These "burn bubbles" are called blisters. It is recommended that you do not pop them. Let them heal naturally on their own. If you do pop them, you risk them becoming infected.
It is applied to the burn because it is an open sore. Whatever you put on the burn is going inside your body, therefore it needs to be sterile to prevent infection.