In which of the following eons did a significant amount of oxygen gas exist in Earth's atmosphere?

a| Hadean

b| Archean

c| Proterozoic

d| No answer text provided.

What is siliceous ooze mostly composed of? a. minerals that crystallize quickly from ocean water through various chemical reactionsB) the shells of diatoms (single-celled algae) and radiolarians (single-celled animals) c.

Describe accuracy, precision and best fit line.

Electrons are a lot lower in mass than neutrons true or false

The highest-pitched sound humans can hear have a wavelength of 0.017 m in air. What is the frequency of these sound waves if their wave speed is 340.0 m/s?

What is the electric flux through the surface a1 that encloses all three objects?

What must be your car's average speed in order to travel 235km in 3.25 hours?

At a certain location, the horizontal component of the earth's magnetic field is 2.5 * 10-5 T, due north. A proton moves eastward with just the right speed for the magnetic force on it to balance its weight. Find the speed of the proton.

An acrobatic airplane performs a loop at an airshow. The centripetal acceleration the plane experiences is 14.7 m/s2. If it takes the pilot 45.

Which of the following was NOT an outcome of Bacon's rebellion? A. A more direct focus on the "Indian Problem" B. A more focused plain to isolate black slaves from white servants C.

A science class did an investigation to see how many breaths it took for each student to blow up a balloon. Jason blew up his balloon with the fewest breaths. Which of these might explain why Jason took fewer breaths to blow up his balloon? A.