Answer: 
Explanation: A double displacement reaction is one in which exchange of ions take place.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Eukaryotic celss have organelles which perform specific functions
Which is a correct description of the organization of subatomic particles in atoms?
Protons and neutrons are tightly packed into a small nucleus. Electrons occupy the space
outside the nucleus
hope this helps.
Answer:
Using the coarse adjustment knob of the microscope in high power may lead to the breaking of the slide if adjusted and raised the slide too much which can damage the sample as well as the high power lens.
In this case, I would recommend using the fine adjustment knob and moving away from the end of the viewing area of the microscope so there would no collision take place. The fine adjustment will help to get a clear image.