The Science test:

is 90 minutes
has no breaks
includes 2 short answer questions that take about 10 minutes per question to write
allows you to use a TI-30XS calculator
gives you an on-screen calculator and allows you to bring in your own TI-30XS calculator

Measures your:

-knowledge of life science (40%), physical science (40%), and Earth and space science (20%)
-ability to read, understand, and interpret science-related texts
-problem-solving abilities in science-related situations