Answer:
B. a piece of paper being torn
Explanation:
A chemical change is one that cannot be reversed. This means the original properties of the substance or object cannot be restored.
If you cook a raw egg, it would turn into a boiled egg (or a poached egg, however it is being cooked). The reaction is irreversible, so you cannot turn the cooked egg back into a raw egg - it is basically impossible to 'uncook' an already cooked egg.
When you toast a piece of bread, it turns into toast. You can't 'untoast' it back into bread. The chemical changes have already occurred and cannot be undone.
If you tear a piece of paper, it is still paper. You are only ripping it, not changing anything about it. You could simply tape the torn bit back to the original bit, or glue it - either way, it is still paper and nothing has occurred to drastically change the physical state of it.
Therefore, B is not a chemical change.
If the distance to a point source of sound is doubled, by a multiplicative factor of 4, the intensity changes.
Intensity of sound is the sound which is perpendicular to sound wave propogation per unit area. It is dependent on the Surface of source sound.
Intensity is the Power per unit area. Its SI unit is Watt/m².
As we move away from a source of sound, the sound starts to diminish. This is due to the decreasing sound intensity with distance.
It can also be understood by the fact that on increasing distance, the Power radiated by the source spreads over a larger area. Hence, the Intensity decreases gradually.
Since, Intensity is proportional to the square of the distance.
Hence, on doubling the distance, Intensity reduces to one fourth of the initial intensity or reduces by a multiplicative factor of 4.
Learn more about Intensity here, brainly.com/question/17583145
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<span> 1.the atom has 7 neutrons and 8 protons....
because the positively charged particles are the protons ...and 8 is also the atomic number ...so number of neutrons can be calculated by subtracting </span>atomic number from the mass number...which gives us the neutrons 7 ...
Hope it helps !!!
