Science Projects Index

Emulsions

Milk and buttermilk are examples of emulsions. If you churn buttermilk you will get butter.

The butter particles are the suspended particles in the buttermilk.

The Valves in the Blood Vessels

There are valves in our circulatory system. In the arteries it is at the starting point. In the veins they are at many places.

They check the reverse flow of blood. Place your hand on the table with the palm touching the table.

Find out the vein on the back of your hand below the middle finger. Press this with one finger and with another finger push the blood in the vein towards the wrist. After the blood has been emptied, take off the second finger. There will be no blood in the vein. This is because of the valves that block the backward flow of blood. When you take off your first finger, the vein will be again filled with blood.