Answer: it's under explanation
Explanation:Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use. Materials from the land's surface can move through the soil and end up in the groundwater.
Answer:
1. An increase in the core temperature
2. A decrease in the core radius.
Explanation:
The sun is a Main Sequence star. A Main Sequence star is powered by fusing hydrogen into Helium within its core.
For this fusion to take place, a temperature of at least 10 million Kelvin is required, beyond this point, the fusion rate is directly related to the core temperature. If the temperature increases, the fusion rate will greatly increase.
Something similar happens if the core reduces its radius. This can happen at the end of the star's lifetime, shortly before it becomes a red giant. Once the hydrogen is depleted, the core will start to shrink because the force of gravity, and as it gets smaller, gets more compressed, and its temperature increases. The outer layers of remaining Hydrogen that were outside the core now begin to heat up, and as the core continues to shrink, the star gets hot enough to begin the fusion process again, and the fusion rate can even be higher than it was during the first phase of the star, as the star becomes a Red Giant.
