Yosemite falls has a total height of 73,900 cm it means it heights 739 meters
The star looks like a desirable hunk of masculinity to Jane. But to John, the star looks like a wimpy momma's boy who might compete with him for Jane's attention. Jane and John have different impressions of the star because of their gender-specific instincts that have evolved during thousands of millenia of human evolution.
Physical changes are those which do not affect the chemical properties of a substance. For example, when a paper is cut, the two pieces obtained are still paper. The chemical properties have not changed. Only, physically when one piece is cut to two. A chemical change occurs when the chemical properties change and a new substance with different chemical properties is obtained. For example, when the paper is burnt, it turns to ashes. Hence, this is a chemical change.
When a substance undergoes a physical change, the physical properties of the substance changes like the state (solid to liquid during melting), shape, size, volume etc. Many physical changes are reversible whereas, in general many chemical changes are irreversible.
Balance tubes by spacing them equally around the centrifuge and Always balance tubes with other tubes containing a same volume of liquid are right.
If you don't space them out equally, you will have a lot of broken glass to clean up...trust me. The same thing can happen if you don't have equal amounts of liquid in each tube, but it doesn't have to be exactly the same in every one.
