What was first responsible for changing the formerly poisonous atmosphere to an oxygen-rich atmosphere as we have today?

Meteor impacts

Volcanic gases

Earthquakes

Photosynethic bacteria (Cyanobacteria)

To what family of the periodic table does this new element probably belong

A sample of 1.000 g of a compound containing carbon and hydrogen reacts with oxygen at elevated temperature to yield 0.692g H2O and 3.381g CO2. a. Calculate the masses of C and H in the sample. b. Does the compound contain any other elements

A person's physical characteristics are determined by their a. environment b. hopes and wishes c. genes d. cells

Which would slow down a reaction that is occurring in a solution at 25 degrees Celcius? Question 11 options: increase the air pressure above the solution add a catalyst put the solution over ice add 10mL of water at 30 degree Celcius

How does technology limit the future of space exploration? A. Scientists are able to work both with current and future technology. B. Scientists must first develop certain technologies before missions can be completed. C.

A critical biotic factor in Yellowstone National Park is A) geographic isolation B) high elevation C) high temperature in the summer D) population of wolves E) proximity to water

If energy can neither be created nor destroyed in a chemical reaction, what can happen to the energy

Effect of ph on conformation of aplha helix

How can we tell when something is polar or non-polar in an Inter-molecular Force?

A reaction is most likely to occur when reactant particles collide with