Tell students that when an atom gains or loses an electron, it becomes an ion. Sodium loses an electron, leaving it with 11 protons, but only 10 electrons. Since it has 1 more proton than electrons, ...

Example: sodium has the electron arrangement 2,8,1. Figure caption, The electron arrangement of a sodium atom. An atom of sodium has 11 electrons. The first two fill the innermost energy level.

Students will be able to interpret the information given in the periodic table to describe the arrangement of electrons on the energy levels around an atom. Skip to Main ... sodium, and potassium all ...

Putting solids under pressure reduces the distances between their atoms, and at extremely high pressures, as electron density increases, all materials approach an ideal metal. Under pressure, then ...

If you are intimidated by the periodic table, then this introduction through the first column of elements will give you a feel for how and why the elements are arranged in this order.

Sodium will lose an electron and form a positive ion. ... (Mg) has the electron arrangement 2,8,2. To become stable it must lose its two outer electrons to obtain a full outer energy level.