Molecular hydrogen, H2, is thought to be the most abundant molecule in interstellar space, but it is difficult to detect. Which easily detected molecule occurs in space along with hydrogen, the measurement of which allows us to estimate the amounts of molecular hydrogen?

Relative Velocity: A pickup truck moves at 25 m/s toward the east. Ahmed is standing in the back and throws a baseball in what to him is the southwest direction at 28 m/s (with respect to the truck). A person at rest on the ground would see the ball moving how fast in what direction?

What will be an ideal response?

Like emission nebulae, planetary nebulae glow because hot stars are causing the gases to ionize when exposed to strong ultraviolet radiation

Indicate whether the statement is true or false

Arrhenius was not particularly alarmed by his discovery at the time. What changed that made later scientists become much more concerned about the climate effects of carbon dioxide?

A. Emissions of carbon dioxide rose much faster than Arrhenius had anticipated. B. Scientists discovered errors in Arrhenius’s calculations that made the effects of carbon dioxide much greater than he had expected. C. Scientists became concerned about carbon dioxide only after measurements showed the world was warming substantially. D. Scientists discovered that there is much more natural carbon dioxide in the atmosphere than Arrhenius had thought.

The chemical recipes of life are stored within each cell as information in _______________ molecules that resemble a ladder with rungs, composed of chemical bases

Fill in the blank(s) with correct word