I can’t tell until he starts school and find out. Most of my students work 15-20 h and biochemistry is one of the hardest major because most students are premed. So it can be done. But someone who has never held a job it might not work. My students mentioned that bookstore job is very flexible (it is student run) and most students get their homework done at job since it’s not very busy place. Plan is for him to try during the first semester. If he can do it fine, otherwise reduce to 10 h. If he can’t manage it with studies, he doesn’t have to work. There are many research opportunities that pay hourly wage and with $15/h now it is a sweet deal. Getting in a lab in the first semester is difficult especially now when most labs are working on reduced capacity.