Answer:
I dont now but I think it is correct
a. The unit cell is the smallest group of atom which have overall symmetry of a crystal, and from which is the entire letters can be buled built up by repetition in 3 dimensions.
b. The volume(v) of the unit cell is equal to the cell edge length (a)cubed.
c. density of polonium is 9.32g/cm3.
The process to create a protected area takes a long time because there's numerous things that have to be taken in account and sorted out before the area gets that kind of legal status.
Usually there's people living in the area that is supposed to be protected, though it is mostly small settlements. The people living there are connected with that area, use the resources, and their lives are largely based and dependent on it. In order for any problems to be avoided, these people should all be educated, deals to be made with them, and properly negotiated so that the area wouldn't have any damage, but also them to be able to sustain themselves.
The boundaries of the area are also complicated, it it takes time to sort out what parts should be included and what not. Basically to set the priorities.
People should be employed to protect and take care of the area, so they have to undergo a training, education, and to get familiar with it.
The legalization of the area as such can sometimes too make problems and take some time.
The correct response I believe is D. The reaction rate increases because the probability of collisions increases as there are more Zn atoms to react.
