Answer:
This matters because you need to know if this site is crediable
Explanation:
You need to know this because you need to know who runs this site and if it was approved by anything crediable.
Atomic theory is the scientific inquiry of the nature of matter, which is subject to change as new information is discovered. The answer is A.
Whether a chemical reaction absorbs or releases energy, there is no overall change in the amount of energy during the reaction. I believe that your answer is to be true.
Answer : Option 3) Electrolysis.
Explanation : In the process of electrolysis, decomposition of the chemical is done by passing the electric current from the liquid or the solution containing ions in it. This is the process where compound is broken into ions namely, cations and anions.
Rest all options does not involves chemical decomposition of the compound.
Chromatography is a technique where rates of solute and solvent are compared in a medium where the solute components move at different rates and the separation is obtained.
Distillation simply purifies the liquid or solution by heating or cooling process.
Filtration just involves removal of impurities by using a more porous material device to get purified compound.
Answer:
D
Explanation:
Gases have low densities. Density is the mass of an object divided by its volume. Mass of gases are quite small. Since the mass is related to mass of the particles itself. However the volume is great since the gases are far apart due to how weak the forces of attraction are ( gases take the shape of the container which means they take up a good bit of space which means greater volume). A small mass divided by a large volume gives a small value (small density).