Respuesta :
Answer:
B. By aligning groups with common properties.
Explanation:
- The periodic table is a table of elements arranged into rows called periods and columns called groups.
- Elements with similar chemical properties are placed in the same group. For example, group 1 elements known as alkali metals share similar properties.
- Elements in the same period or low have the same number of energy shells or energy levels. For example elements in period 3 have 3 energy levels.