Presumptive tests, also known as preliminary tests or field tests, allow drugs to be quickly classified into a particular chemical group, but do not unequivocally identify the presence of a specific chemical compound.
That would be either, nuclear power or wind power, depending on what the teacher is looking for...
Potassium has 20 neutrons
Hope this helps
In particles physics, the weak interaction (the weak force or weak nuclear force) is one of the four known fundamentals interactions of nature, alongside the strong interaction, electromagnetism, and gravitation.
This is based on my research, hope it helped :) <span />
A bike rusting is an example of a chemical
change since rusting is a chemical reaction. New substances are formed from
this reaction. On the other hand, other choices given are just physical changes
because only the shape or the physical form of the substances are being
changed. An example of a physical change is cutting a paper.