(2) Arsenic. It is an element and elements are chemically the simplest units and cannot be broken down by any chemical change.
Answer : The correct answer is option C.
Explanation:
Astronomers have observed that light from the distant object in the universe is shifted towards the frequency of red color which indicates that those object are receding or moving away from the planet earth.This phenomena was termed as Red shift .Same thing goes for galaxies which are very far away from the planet earth.
Where as if galaxies were moving towards the the planet earth their light would have shifted toward the frequency of blue color termed as blue shift.
Hence, the correct answer is option C.
A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction.
If there is an increase in industrial activity, that means that more heat will be dissipated to the atmosphere in the form of carbon dioxide. Industrialization requires fuel to keep the processes on the go. At the end of the pipeline, the combustion of fuel would result to carbon dioxide released to the atmosphere. That's how it is contributing to the global climate change through the greenhouse effect.