In the detention room is a green cabinet.After you set off the stink bomb (made from blue and yellow liquid in the science lab) click the cabinet then go down. Turn the light on.On the ceiling about in the middle of the room is the clapper.
The clapper.
It it in the secret passage in the detention room on Big Nate Island.
The missing bell clapper on big nate island is in the secret room under the detention room turn on the light and go to your right and jump on the tool table and above you is the missing bell clapper just jump at it and it will go into your items.
get the bell clapper
The bell on Big Nate Island on poptropica is located on the top school building. To reach it when you have the clapper, you need to get rid of the seagull there. (see related question)
The missing bell clapper on big nate island is in the secret room under the detention room turn on the light and go to your right and jump on the tool table and above you is the missing bell clapper just jump at it and it will go into your items.
The missing bell clapper is hanging from the ceiling.
you go on top of the school and there no clapper so you sneak off with the egg
you first have to find the clapper for the school bell so they will leave
The clapper allows you to fix the bell on top of the school, which is guarded by a nasty seagull. Get him to move and you can fix the bell. (see related questions)
Get the clapper. Then go out and put the clapper on the bell (outside of the school)
by the green cabnit and what is useful in the secret room is the bell clapper