PLEASE HELP DONT SKIP ANSWER.

Explanation:

Remember that a physical change only changes the appearance, while a chemical change creates completely new substances. Also, note that there are 5 main signs of a chemical change:

In this experiment, acid was added to a piece of metal. Bubbles formed and the metal turned black. Therefore, 2 signs of a chemical change occurred. The metal changed colors and a gas was formed, signified by the bubbles. So, the best answer choice is C: A chemical change because a new gas was formed.

the correct answer: the index of refraction of the second medium is lower i tried this persons answer and it was wrong this person is lying

answer: grassland biomes are closer to the equator and receive more rain.

grasslands are biomes that are dominated by grasses rather shrubs and trees. savanna are biomes that exhibit grasses, shrubs and small tree as vegetation. grasslands are located near the equator of the earth. these are found in north america. savanna biomes are found in africa, south america, australia and india. grassland exhibit moderate climatic conditions, it receives   amount of rainfall higher than savanna.   therefore, savanna exhibit dry and hot climatic conditions.