How are cyanobacteria related to the increases in oxygen levels of the atmosphere?

How do you date a sample of rock that you suspect as being one of the earliest on earth

Im inn a ! what"s the answer which of the following is one way creativity can scientists? by ensuring they follow the scientific method by increasing the amount of time it takes to complete scientific experiments by making sure they only try things that have already been proven by leading them to ask more questions about the natural world

20 the compound al(nh3)2 has atoms of nitrogen.