science education resource


To view these resources with no ads, please Login or Subscribe to help support our content development.

School subscriptions can access more than 175 downloadable unit bundles in our store for free (a value of $1,500).

District subscriptions provide huge group discounts for their schools. Email for a quote:

Diffusion is the spreading out of a gas until it is uniform everywhere. In other words, the oxygen flows from the blood into the alveoli because there is more oxygen in the blood than in the alveoli and diffusion seeks to make the amount in both places equal, so it flows across the membrane. has more than 2,000 illustrated animals. Read about them, color them, label them, learn to draw them.