Video Transcript
An atom of silicon has an atomic number of 14. How many electrons are there in an atom of silicon?
Atomic number, represented by Z, can be used to distinguish one element from another, as each element has its own unique atomic number. When looking at a cell on the periodic table, the atomic number is frequently written above the chemical symbol. The atomic number also represents the number of protons in the nucleus of all atoms and ions of a particular element.
In the question, we are told that an atom of silicon has an atomic number of 14. This means that an atom of silicon contains 14 protons. The question asked us how many electrons there are in an atom of silicon. To determine the number of electrons in an atom of silicon, let’s think about the components of an atom. Atoms are composed of positively charged protons, negatively charged electrons, and neutral neutrons. Although atoms contain charged particles, they are overall electrically neutral. So let’s think about the charge contribution of each type of particle in our atom of silicon.
14 positively charged protons will have a charge contribution of 14 plus. We don’t know how many electrons the atom of silicon contains, but we do know that electrons are negatively charged. So their charge contribution will be negative. We have not been given any information regarding the number of neutrons in our atom of silicon. But regardless of the number of neutrons in our atom of silicon, the charge contribution from the neutrons will be zero, as neutrons do not have a charge.
As atoms are electrically neutral, the sum of the charge contributions must be equal to zero. Therefore, in order to cancel the charge contribution of the protons, the electrons must have a charge contribution of 14 minus. As each electron has a negative charge, there must be 14 electrons in the atom of silicon. So an atom of silicon that has an atomic number of 14 has 14 electrons.
