What two recurring events in earth's history have an impact on the carbon cycle?

1.volcanoes erupt.

2. Fossil formation.

Explanation:

1. The volcanoes vent gas to the atmosphere, they emit between 130 and 380 million metric tons of carbon dioxide per year.

2. Heat and pressure compress organic carbon (carbon from living organisms) embedded in layers of mud. By this process sedimentary rocks are formed.

they float because they are less dense than the water itself

something denser than water, like a rock, will sink to the bottom

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation: