Calculate the number of atoms in a 7.91×103 g sample of calcium.

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.

Identify the electromagnets with poles that are reversed from the electromagnet shown above

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.