Its probably best to ask individual unis, as my uni is very different to the students Emily has.
We do in first year:
Around 12 weeks in uni, then 10 weeks of placement (split into 2 as we have christmas and exam week in the middle) then around 10 weeks maybe in uni, and then another block of placement.
Then second year is sort of opposite, and 3rd year is the same as first. So each year we have 2 blocks of placement and 2 blocks of uni