QUICK QUESTION: On the Bohr model, how come potassium has 19 electrons in its valence shell if potassium has a K+? Isn’t it suppose to have 18 electrons? I thought that if an ion has a positive charge, the atom has lost electrons. Pls help me

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian bought 4 bottles of water and 1 cup of coffee for his family for $7.15. how much does each bottle of water cost? how much does each cup of coffee cost? i need this done

Olga used 100 ounces of flour to make 225 muffins. how many ounces of flour will be used to make 300 muffins?

Solve for x where 0 equation: cot^2x+2cotx+1=0