Sodium melts at 98 °C, and magnesium melts at 650 °C. Account for the higher melting point of magnesium using the electron-sea model.

Video transcript

Hello everyone today. We have the following problem explain the difference in the melting points of potassium and calcium. Using the electron C model first, it's important to note a couple of key factors. potassium Is a group 1 8 element and therefore has one valence electron calcium, on the other hand is a group to a element and therefore has two valence electrons. Additionally in this sea of electrons because electrons behave in a sea, they're just floating around essentially each potassium because it's a group one a element gives up one electron or it donates that electron to the electron C. Whereas each calcium adam gives up or donates two electrons to the electronic see. So in a sea of electrons, these two Electrons from Calcium are present and one from potassium. And so lastly to tie this all up, the more electrons we have, this is going to directly correlate with a greater electrostatic force. So if you think about it, the more electrons we have, the greater the force we have which will subsequently lead will lead to calcium having a higher melting point as we see in the question stem. And so this leads us to answer choice. D calcium has a stronger has strongly electro static force is causing it to have a higher melting point. And with that we've answered the question overall. I hope this helped and until next time