Ques: Q: What do corals secrete that builds up to become a coral reef? Choices: - membrane - mucous - scales - exoskeleton A:
Ans: exoskeleton

Ques: Q: Before the atmosphere became oxygenated, the planet was subjected to what harmful energy source, meaning the first organisms would have flourished where they were more protected? Choices: - evaporation - conduction - convection - radiation A:
Ans: radiation

Ques: Q: Iron is oxidized to fe2+(aq) at an anodic site on the surface of the iron, which is often an impurity or this? Choices: - displacement defect - spontaneous mutation - ladder complex - lattice defect A:
Ans: lattice defect

Ques: Q: Water is a polar compound, so its molecules are attracted to each other and form what kind of bonds? Choices: - mixed - carbon - helium - hydrogen A:
Ans:
hydrogen