Pi and sigma bonds
Pi is double bonds and sigma is single bonds
So, we know that a metamorphic rock is either an igneous or a sedimentary rock that are exposed to intense heat and pressure.
But when the metamorphic rock is thrusted deep underground through subduction, it will again be subjected to intense heat. This can cause it to melt, turning it into a magma. When the magma cools down, it again becomes an igneous rock and the rock cycle continues.
The scientific study of the biological aspects of social behavior in animals or humans! Hope this helped.
The studies are designed this way b/c it removes the power of suggestion and the double-blind study keeps both researchers and participants in the dark. So this compared to who is receiving the treatment which is relevant b/c it stops the researchers from accidentally overbalancing the study participants, or unintentionally favoring their assessment of the conclusions.