Which electron configuration represents a selenium atom in an excited state? (1) 2-7-18-6 (2) 2-7-18-7 (3) 2-8-18-6 (4) 2-8-18-7

An unidentified compound contains only phosphorous and fluorine, meaning we could write its formula as PxFy. Heating 0.2324 g of the compound in a 378-mL container converted all of it to gas with a pressure of 97.3 torr at 77°C.

Lewis model hydrogen and nitrogen

At equilibrium, what is the rate of production of reactants compared with the rate of the production of products? A.) much higher B.) higher C.) the same D.) lower

9.87 g of calcium sulfate and 12.05 g of potassium react. What is the total amount of potassium sulfate that can be produced?

50.0 grams of acetic acid are required for an experiment. What volume, in milliliters, of a 1.105 g/cm3 acetic acid solution must be measured for the experiment?

Where did the earth hold most of its original water

Giovanni created this chart to study for an exam. A 2-column table titled common ionic compounds. The first column labeled compound has entries sodium hydroxide (N a O H), iron oxide (F e O), calcium chloride (C a C l subscript 2), calcium carbonate

Consider the two electron arrangements for neutral atoms A and B. What is the difference between atom A and atom B? A - 1s22s22p63s1 B - 1s22s22p65s1 Atom B has lost some inner electrons.

Choose all the answers that apply. Which of the following has kinetic energy? rolling ball, moving car, book on a table, spinning top, or a falling tree.

Which of the following statements about the suns feature is true?