How old are your chicks? Do you have them in a brooder with sufficient food for the time you will be gone.? Do you have shallow water pans with some clear pebbles or marbles in them - to prevent drowning. Is there a wire top on your brooder, so they have good air exchange, and to prevent any from flying out, or house pets from getting in to harm them? Do you have enough room for them in the brooder so they are crowded?
How long are you gone on school days? I think if you check for pasty butt before you leave in the morning and again when you come home - they should be alright. Chicks grow very fast. Will you have a secure coop and covered run for them to be in once they are old enough to move outside?
You may want to read through the Learning Center,for the answers to many, many questions. It's a good start for newbies. Welcome to Backyard chickens. What breeds did you get?