21. Making Inferences A light green powder is heated in a test tube. A gas is given off, and the solid becomes black. In which classification of matter does the green powder belong? Explain your reasoning. I

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of tthe table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.