Size of atoms
Size: more electrons, larger size? The graph shows the atomic radius of the elements against their atomic number. What conclusions can you draw?
The original interactive periodic table, made in Flash, no longer works in current browsers; the image shows one of its views.
The graphic shows the size of atoms in ångströms (0.000000001 cm). The size of the circles displays the relative size of atoms. The atomic number indicates the number of protons within the nucleus (and electrons in the periphery) of the atom in question.
- Going down a group of atoms (column of the Periodic Table), atoms increase in size.
Going down, the outermost electrons reside in shells farther from the nucleus and the size of atom increases.
- Going to the right hand side (row of the Periodic Table), atoms decrease in size.
When progressing through a row (period of the Periodic Table), new electrons are added to the same shell but protons are also added at the nucleus. The new protons exert an additional attraction to the electrons, thus compressing the orbitals from one atom to the next, progressively diminishing the size.