Which of the following does NOT exist as a giant covalent lattice? * Graphite Sodium chloride Graphene Fullerene Diamond

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

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?

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?