D)By increasing or decreasing the size of systems that are difficult to study we make it easier for students to see how they work and therefore make it easier for them to learn.
Explanation:
Scientific models makes it easier to teach students about systems because their sizes can be adjusted and this makes it easier for students to see how they work.
A model is a simplification of the real work. It takes a part of the real world and studies it.
Models are highly desired in teaching and understanding very complex systems.
Since a tutor owns the control of the model, they can make adjustments on them to a scale that is convenient to work with.
Also, a part of a system can be studied one at a time making it simple for students to comprehend.
A, radium-228. Alpha radiation is essentially just two protons and two neutrons leaving the atom, causing the atomic number to drop by two (since the protons left) and the mass number to drop by four (since two neutrons and protons left).
