Can anybody give me some info about inodes?

[Kaustubh Ghosh]

Hi all,
I am new to this list and I have a question:
Can anyone please tell me the answers to the following:
  1.How many inodes are there in a single block ?
  2.After a inode is deleted , is it appended to the end of free inodes list?
  3.Is there any preference in which the inodes are allocated in choosing 
between inodes that has never been allocated and inodes which were once 
allocated but are now free?
  4.Doess the data in an inode remains unchanged when it is deleted?

Please consider the ext2 file system  while answering my query

It would help me immensely if I get the answers to the above.Thanks in advance 
for all the help you can give.

Thanks,
Kaustubh Ghosh