Junior is reading a scientific tome entitled How to Isolate the Isotope.
Although the background artwork had become a bit more abstract and modern, as mid century design became the standard, it was no less colorful or detailed than the work that came before.
Chicken croquettes is another name for chicken meat patties. They are traditionally coated in breadcrumbs and served in a cream soup sauce. The shape can either be a patty or a rounded ball.