Почему число элементов в периодах соответствует ряду чисел 2 – 8 – 18 – 32? Разъясните эту закономерность с учетом расположения электронов по энергетическим уровням

in my fridge to eat butter, meat, ketchup, eggs, milk. Milk white and useful, so I drink it. In the fridge there is still ketchup, it is made from tomatoes. Meat is different: chicken, pork. Protein contained in the eggs. Oil albeit greasy, but tasty! The fridge is still stored beverages that they were not warm. Cola for example, tastes better cold. Yet there is a department in the refrigerator: freezer. There and then stored meat!