<span>The first method to determine the chemical composition of a substance in space was using light. By determining red shift in the observed spectrum of light they could determine the elements they were observing. Different elements change the way light behaves and from this scientists can determine the makeup of things such as stars and nebulas.</span>
The answer to this question is 2 and 3
A scale and a ruler. The scale to measure the mass, and a ruler to measure the volume.
Aluminum is more reactive than iron
but it forms Al-oxide, that form a thin layer on the surface of Al, and protect Al from reaction with water.
Answer: Very unreactive aluminum oxide forms a thin layer on aluminum.
