<span>(P1/T1) = (P2/T2)
T must be in kelvin first!</span>
ANSWER
2 valence electrons
STEP-BY-STEP EXPLANATION:
The electronic configuration is given below as

Looking at the configuration, you will see that the last energy carries 2 electrons
Hence, the valence electrons are 2
True when the boron control rods are lowered it slows the reaction