It’s 8 electrons. “octa” means 8
Answer:
The Bowen's reaction series describes how minerals form in sequential order, forming at higher temperature to a lower temperature. There are two branches of crystallization, one is the continuous branch that is on the right and the other is the discontinuous branch that is on the left.
The minerals that are at the top of the Bowen's reaction series forms at a higher temperature.
In the discontinuous branch, the first mineral to crystallize from the melt is Olivine that forms at a higher temperature of about 1400°C. After crystallization, some melt remains and undergoes fractional crystallization leading to the formation of Pyroxene. Again, with the remaining melt, it reacts and forms Amphibole, followed by Biotite (mica).
In the continuous branch, the first minerals to form are the calcium-rich minerals and successively forms sodium-rich minerals. These minerals that form at a higher temperature are basic in nature and gradually change into acidic minerals.
From both the branches, it commonly forms the mineral Potassium feldspar. After this, the remaining melt combines with the magma and forms Muscovite (Mica), and at a temperature of about 650°C, it forms a more resistant and stable mineral known as the Quartz.
Odd, unusual, or unexpected.
