Answer:
Early-warning systems are essential in the case of hurricanes, severe thunderstorms, tornadoes, tsunamis, and volcanoes. All of these can wreak havoc! Let’s take a look at how meteorologists forecast these events and how early-warning systems can help us protect ourselves if we are in their paths.
Explanation:
Chemical changes only happen when the object changes form. Color is a physical property because you're not changing the object that you have, compressibility is also a physical property because you still have the same substance before and sfter, malleability again is another physical. Heat of combustion is physical, when you burn things it changes the substance. :)
Physical change alters a given material without changing its chemical.
The layer that doesn't exist at all is the l<u>ithosphere</u> because the very last level of the entire atmosphere is the exosphere.