Which of the following is a sign of a chemical change? * Change in shape
Melting from solid to liquid
Formation of a precipitate
Change in size

Melting from a solod to liquid

Explanation:

the other choices are all physical changes because the object has not changed chemically

why is arctic sea ice important? arctic sea ice keeps the polar regions cool and moderate global climate. sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space. as sea ice melts in the summer, it exposes the dark ocean surface.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.