Periodic Trend: Effective Nuclear Charge

now within an atom and electron experiences two different forces it experiences and attraction by the nucleus and a repulsion by surrounding electrons. So let's say that we're examining this electron here. Well, the electron here is negatively charged, so it would form an attraction to the nucleus here, which is positively charged at the same time, this outer electron here, since it's also negative, would repel this highlighted electron. So these electrons are experiencing these two different forces at the same time, attraction for the nucleus. But repulsion from one another now effective nuclear charge abbreviated as Z E f is the measurement of attractive force between protons and electrons. So here, the attractive force between that electrons and the nucleus can be explained by the effective nuclear charge. We're going to say here that the greater the effective nuclear charge than the greater the attractive force between the nucleus and the electron. And if you're attracted to one another, you're gonna come closer together. So the electrons are gonna be pulled closer to the nucleus. At the same time, we have our shielding constant. Now our shielding constant is the measurement is the measurement of the repulsive force between our valence electrons or outer shell electrons and the inner core electrons here. We're going to say as that increases, that's going to cause an increase in the repulsive force. So Valence electrons are gonna be pushed further away from the nucleus here. This electron and blue is experiencing pushing away because the electron that's highlighted is repelling it further and further away from the nucleus. So just keep in mind we have these two forces at work within any given Adam.