What is the oxidation number of chromium in dichromate ion, cr2o72-?

Asap! ! who wants to me with my assignment : ) (especially with how i’m gonna draw out the example) you have explored some interesting, informative, and amusing examples of models. now it's time to get creative and make your own model. here is the requirement checklist for your model: ✔ model types can include drawings, diagrams, physical models, virtual simulations, or videos. ✔ models must be created by you, not something selected from an online or outside source. ✔ submit a presentation, picture, video, or screenshot of your model. ✔ submit a one-paragraph summary describing the topic you chose, your model, what it represents, how you made it, and the specific science involved. it is important that you are using science terminology and are accurate. now that you know how to create and submit your model, you will need to choose a topic for your model. choose one of the three topics listed below. select each topic for an overview. -conservation of mass -atomic theory -thermal energy

What is the molecular formula for a compound that is 46.16% carbon, 5.16% hydrogen, and 48.68% fluorine? the molar mass of the compound is 156.12 g/mol

If 1.8 l of water is added to 2.5l of a 7.0 molarity koh solution, what is the molarity of the new solution