When silicon atoms bond, then silicates form which are minerals in which such elements as potassium, calcium, magnesium and aluminum combine with the silicon atoms to form minerals like feldspars of different types or if it is just silicon and oxygen that bond then it forms quartz.
a solar eclipse, when the moons shadow comes between the sun and earth
The Union lost the Battle of Fredericksburg because Burnside was unable to adapt to changing circumstances.