The atomic number of an element that has 9 protons 9 electrons and 10 neutrons is?

Which of the following statements is true about planck’s law

Identify one disadvantage to each of the following models of electron configuration: -dot structures -arrow and line diagrams -written electron configurations type in your answer below. (answer) -dot structures do not show the distribution of electrons in orbitals and take up a lot of space. -arrow and line diagrams take up a lot of space and make it difficult to count electrons. -written configurations make it easy to lose count of electrons and do not show the distribution of electrons in orbitals.

In 2002, the rare earth elements mine in mountain pass, california was closed because