which has a higher zeff sodium or magnesium? and how can you tell based on physical observations or characteristics.

In an energy pyramid, which level has the most available energy?

Calculate the number of moles of ethane in 100 grams

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?