Q: What is the layer above the troposphere? Choices: - sediment - condensation - earth - stratosphere A:
stratosphere

Q: If heat is released by the system into the surroundings, a chemical reaction or physical change is called what? Choices: - static - endothermic - biochemical - exothermic A:
exothermic

Q: Q: Each enzyme has an optimal what at which its reaction rate is greatest? Choices: - weight - size - precipitation - temperature A:
A: temperature

Question: Q: Substances that act as both weak acids and bases are said to be what? Choices: - amphiphilic - hygroscopic - atmospheric - amphoteric A:
Answer: amphoteric

*Question*
Q: Arrows and cannon balls are examples of objects with what kind of motion? Choices: - velocity - fluid - accelerating - projectile A:
**Answer**
projectile

Q: What is one method to observe nebulae? Choices: - mirror - kaleidoscope - microscope - telescope A:
telescope