Answer:
1 = A
2 = B
3 = B
Explanation:
1) Black holes occur when really big stars collapse on themselves. And, in order to get big, the star has to be an old one.
2) A black hole is something huge that swallows up everything, while a protostar is just the very beginning of a star.
3) Scientist can't truly know for sure, but they can infer about them due to the effects of the surrounding areas.
Answer:
No, bottled water cannot go bad.
Explanation:
It is impossible for any sort of water to "expire". But, when in the bottle for to long, the plastic does become dangerous. The bottle begins to leak chemicals into the water. This doesn't make the water toxic, but it can alter the taste of your water.
This was Ernest Rutherford’s gold foil experiment. He used radioactive alpha particles as a part of the experiment and discovered that there was a densely packed, positively charged nucleus in atoms with electrons that were spread out in spaces between nuclei.
Answer: D
Explanation:
During the process of photosynthesis the plant would use carbon dioxide, sunlight and water in order to produce and release sugar and oxygen back into the air.