Question

a mid - ocean ridge is located at the boundary of two tectonic plates. which diagram correctly models the relative plate motion on each side of a mid ocean ridge?

Explanation:

Mid - ocean ridges are formed at divergent plate boundaries, where tectonic plates move away from each other. In the yellow - colored diagram (first one), Plate 1 is moving left and Plate 2 is moving right, which shows the plates moving away from the ridge (since the ridge is between them, moving in opposite directions away from the ridge line). The purple diagram shows plates moving towards each other on one side, the orange shows convergence, and the teal shows vertical motion (not typical for mid - ocean ridge plate movement). So the yellow diagram (with Plate 1 arrow left, Plate 2 arrow right, and ridge between them) correctly models the divergent motion at a mid - ocean ridge.

Answer:

The yellow - colored diagram (the first one, with Plate 1 having a left - pointing arrow and Plate 2 having a right - pointing arrow, and the ridge between the two plates)