Fairfax County students are scoring lower on science exams than the school system had hoped, especially at the elementary level, and probably will not meet next year’s performance goals, school officials plan to tell the school board Thursday night. The school board also will be disappointed by the racial achievement gap, said Myra Thayer, PreK-12 science coordinator for Fairfax County Public Schools.

Eighty-six percent of fifth-graders passed the Virginia Science Standards of Learning test or an alternative assessment, fewer than school officials had projected — and a percentage that didn’t budge from the 86 percent average of 2005, 2006 and 2007 scores used by the district for comparison. The number of students scoring “advanced” slipped from 21 percent to 20 percent, far behind the district’s goal of 33 to 49 percent.