Since invasive species did not co-evolve with the other species in the ecosystem where they were introduced . a.
they can unbalance the ecosystem
b.
they are considered a serious environmental problem
c.
they lack natural predators to help control their population
d.
all of the above

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

In an experiment, how can i change human errors? be specific.

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell