What was the biggest difference between the Earth's second atmosphere and third (present) atmosphere? Carbon dioxide from volcanic activity became a major part of the atmosphere.

Oxygen from plant photosynthesis became a significant part of Earth's atmosphere.

Oxygen from water vapor in the atmosphere became a large part of Earth's atmosphere.

High percentages of Carbon dioxide caused a sustained warming cycle 500 million years ago.

A2 cm object is 10 cm from a convex lens that has a focal length of 4.4 cm, the image is 8cm from the lensz the height of the image, to the tenths place is

15 points need quick 1. looking at your graph and the geologic time scale during what period did this rock form? what is the age span of the rock, in millions of years? 2. this rock sample is limestone and shale. with what you know about rock formation, what type of environment did these organisms live in? 3. if some of these fossil samples were found in a rock also containing leaf fossils, could you use radiocarbon dating to determine the age of this rock? explain.

Which of these is most likely a characteristic of a non-radioactive daughter isotope after it is form from the parent isotope a . stable electron’s b. stable nucleus c. positively charged atom d. negatively charged atom