Best science project for class7

Well firstly you can do an landscape of an poster about adding 8 planet in the solar system.

Explanation: you can be creative like adding the each and every planet.

to be honest its up to you, I just gave you an headstart

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.