17. Which of the following lists contains only elements and a reason why they are elements
C12, H2, Na, He - Substances are elements because they are pure.
H, O, NaCl, N2, CO2-Substances are elements because they
contain more than one chemical symbol
Kr, Ne, Ar, He - Substances are elements because they are all noble
gases.
F3, Os, Li, H-Substances are elements because they all have
chemical symbols.

In which phase(s) do the molecules take the shape of the container?

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.

Which statement best describes the flow of energy in this scenario