1. the boys were hit by a(n?) (atom?) bomb
2. the "scar" is the crash site made by the plane in the jungle
3. piggy found the conch that is used to summon the boys by ralph. piggy has asthma, so he couldnt use the conch because he would run out of breath
4. ralph is chosen to be chief because he has the conch
5. jack is the leader of the hunters. the hunters are members of the choir and jack is the leader because he is 'chapter chorister and head boy'