How to Label the Shells of an Atom

Choose an Atom

• 1

  Choose an element. The electron shells of each atom differ depending on the atom̵7;s identity as an element. For example, the labeled shells of a hydrogen atom are very different from the shells of a francium atom.

• 2

  Learn the atomic number of the substance you̵7;ve chosen to draw. You can do this by locating the chosen element on the periodic table. The number either directly above or below the element̵7;s symbol indicates the atomic number.

• 3

  Determine the number of electrons in one atom of the chosen element. The atomic number refers to the number of protons in an atom of the element. In a neutral atom, the positively charged protons are evenly balanced by the negatively charged electrons. Therefore, the atomic number also gives you the number of electrons in an atom of the element.

Draw a Representation

• 4

  Get out a sheet of blank paper and a writing utensil and draw a rough representation of an atom. Start with a small circle in the center of paper, which represents the nucleus. Write the number of protons of one atom of the chosen element inside the circle, using simple notation such as ̶0;P=4̶1;.

• 5

  Draw a larger circle around the nucleus of the atom, leaving some space between the concentric circles. This is the first electron shell. Electron shells are either labeled alphabetically starting at ̶0;K̶1; or numerically starting at ̶0;1.̶1; Choose a labeling method and write down either ̶0;K̶1; or ̶0;1̶1; next to the first electron shell. Draw two dots along the circle indicating the two electrons which the K shell contains.

• 6

  Draw a second circle representing a second electron shell if your chosen element has an atomic number higher than two. Label the second shell ̶0;L̶1; or ̶0;2.̶1; Draw eight dots along this circle to indicate the eight electrons that the second shell contains. If your element contains fewer than eight and more than two electrons, only draw enough dots to represent all needed electrons along the two shells.

• 7

  Continue drawing concentric circles and labeling them either numerically or alphabetically until you have enough dots to represent the number of electrons in the atom. The third shell contains 18 electrons, the fourth contains 32 electrons, and the number of electrons in further shells can be determined by the general formula 2*n-squared, where ̶0;n̶1; is equal to the shell number. Once you have finished placing dots to represent electrons, you have successfully labeled the shells of an atom.