What organelle is found only in plant cells, provides structure and support outside of cell, and protect the plant and provide rigid support

There is an area in idaho named craters of the moon where most of the ground is covered with basalt, adark gray, igneous rock with no visibl crystals. what can you infer about the geographical history of the area?

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

What is a number added in front of a formula in order to balance the equation