1. Put the following elements in order of increasing first ionization energy: Ar, Ca, Mg, O, N, At

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.

Why is the melting of ice a physical change ?

When did stem cell research become known ? who discovered stem cell? what experiments or studies have been conducted so far?