The organisers of next year's RDS Primary Science Fair have seen a 43% increase in applications.
The fair, which runs at the same time as the BT Young Scientist and Technology Exhibition, is oversubscribed by 130%, with half of schools being first-time entrants.
More than 2,700 pupils from 120 primary schools across the country will exhibit their projects.
The topics include "Do cows have blue eyes?", "Why don't aeroplanes fall from the sky?" and "What type of cup keeps liquid hot the longest?".
The fair runs from 8-10 January and encourages primary school teachers to focus on developing students' core scientific skills by investigating a question or problem by "working scientifically" and "designing and making".
The aim is to develop science and mathematical skills in primary school-aged children by fostering education innovation.