Final answer:
To determine whether an element is showing or hidden, you can refer to the menu options in a software or program. For example, selecting the 'show' option makes the element visible while selecting the 'hide' option hides the element. In the given scenario, the iron in the flour is visible while the sugar in the water is hidden.
Step-by-step explanation:
In this case, the student mentions specific menu options such as 'Actions... Atoms/Bonds... show' and 'Actions... Atoms/Bonds... hide' which suggest that these options can be used to control the visibility of elements.
For example, if you select the 'show' option, it means that the element will be displayed and visible. On the other hand, if you select the 'hide' option, it means that the element will be hidden and not visible.
In the given scenario, you can see the pieces of iron in the flour because they are not hidden, but you cannot see the sugar in the water because it is hidden.