Q: What do scientist's believe mercury's core is mostly made of? Choices: - water - quicksilver - helium gas - melted iron A:
melted iron

Q: What is the distance that sound waves travel in a given amount of time called? Choices: - velocity of sound - momentum of sound - force of sound - speed of sound A:
speed of sound

Q: Q: Frogs are amphibians that live part of the time in fresh water and rest of the time where? Choices: - underground - in stagnant water - in salt water - on land A:
A: on land

Question: Q: The force applied to an object is called? Choices: - gravity - torque - strain - stress A:
Answer: stress

*Question*
Q: What process is magnesium important to? Choices: - dna replication - carbon cycle - absorption - photosynthetic A:
**Answer**
photosynthetic

(Q).
Q: What is used for cooling detectors of infrared telescopes? Choices: - hand nitrogen - material nitrogen - carbon dioxide - liquid nitrogen A:
(A).
liquid nitrogen