So i can do 7 normal subjects and 1 breath in first year?!
Yes, as long as you're prepared to miss out on subjects taking your minimum breadths in other years.
You can take a breadth every semester if you want to but you don't have to - I've only done the minimum of four.
The only rules are that no more than three of the breadth subjects can be Level 1 ie at least one subject must be at Level 2 or Level 3. But you could take the Level 1 breadth you didn't do this year in your second year if you want to make room for Physics now and think you will have room for it next year.
Here is a quote from the handbook if you're unsure!:
"Students commencing the BSc from 2011 onwards
Successful completion of 300 points comprising:
225 points of science subjects including:
At least 62.5 points at Level 1
At least 62.5 points at Level 2
At least 75 points at Level 3 (including 50 points of a prescribed science major at Level 3)
50 points of breadth subjects including at least 12.5 points at Level 2 or Level 325 points (either science subjects or breadth subjects) at Level 1, 2 or 3"