Contrary to popular belief the scientific method is an iterative process because scientists often have to revisit, repeat or revise previous steps. It is very common for an experiment to be done many times in different international laboratories in order to confirm that a conclusion is valid. All good scientific experiments should allow results to be replicated.
Explanation:
Chemical formula of gypsum is and it is a soft sulfate mineral that consists of calcium sulfate dihydrate.
Some uses of gypsum are as follows.
- It is used for manufacturing wall board.
- It is used in the manufacture of plaster of paris.
- It is also used as a fertilizer.
Thus, we can conclude that out of the given options, fertilizer, wallboard, and plaster of paris are some uses of the mineral gypsum.
Answer:tetrahedral
Explanation:
According to Valence Shell Electron Pair Repulsion Theory (VSEPR). The number of electron pairs on the valence shell of the central atom in a molecule influences the shape of that molecule. Four electron pairs around the central atom of a molecule leads to a tetrahedral geometry as predicted by VSEPR.
Answer:
z+4
Explanation:
An isotope of an element, atomic number Z, has a mass number 2z+4. How many neutrons are there in the nucleus of the element?o
protons + neutrons =mass number
so
z +neutrons = 2z+4
neutrons = 2z+4 - z=z+4 which is the # of neutrons in the nucle
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