(Q).
Answer the following question given this paragraph: Burning of fossil fuels, such as oil, releases carbon into the atmosphere. This carbon must be cycled - removed from the atmosphere - back into living organisms, or it stays in the atmosphere. Increased carbon in the atmosphere contributes to the greenhouse effect on Earth. Q: Carbon released by burning fossil fuels contributes to what effect in the atmosphere? Choices: - shielding effect - smog effect - cloud effect - greenhouse effect A:
(A).
greenhouse effect

(Q).
Answer the following question given this paragraph: Oxygen has 6 valence electrons in its ground state. Remember that ground state refers to the neutral atom in which the electrons occupy the lowest possible energy positions. Oxygen is two electrons away from being isoelectronic with the nearest noble gas. Oxygen will therefore form ions by gaining two electrons to become isoelectronic with neon, as shown below:. Q: What kind of energy positions do electrons occupy during ground state? Choices: - closest energy positions - relative energy positions - highest energy positions - lowest energy positions A:
(A).
lowest energy positions

(Q).
Answer the following question given this paragraph: No physical object can travel faster than the speed of light in a vacuum. (Maximum speed is finite). Q: Genetic variation helps ensure that some organisms will survive if what happens? Choices: - they get eaten - there's an earthquake - they die - their environment changes A:
(A).
their environment changes