# An atom of a chemical element contains 15 electrons. how many of them are on the external energy level?

August 28, 2021 | education

| There are 5 electrons on the outer energy level. To find the number of such electrons, there are 2 options: either look at the periodic table (the number of external electrons is equal to the group number), or calculate (at the first energy level there are always 2 electrons, on the next 8, we are given 15 electrons, => from 15 we subtract 2 and 8, we get 5)

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.