Expand Raid 1 to Raid 5 issue

R430 with PERC H730 Mini

existing there are 2 x 500Gb hard disk and setting Raid 1, 

now want to add 1 x 1TB hard disk.....

1. it must change to Raid 1 to Raid 5 in order to add 1TB hard disk?

2. it is available to set Raid 5 with 3 hard disk with  2 x 500Gb + 1 x TB, although different capacity?

3. if available, will it loss data after changing from Raid 1 to Raid 5 ........?

Thanks for help and advise!