An atom has an atomic number of 9 a mass number of 19 and an electron configuration of 2-6-1 explain why the number of electrons in the second and third shells shows that this is in an excited state

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

What is the value of keq for the reaction expressed in scientific notation?

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.