Which of the following has had the most negative effect on Earth's ecosystems? A. establishment of air pollution standards.
B. increase in human population
C. recycling glass, plastic, and metals
D. use of natural predators to control pest insects.

In an oxidation-reduction reaction, oxidation is what happens when a reactant

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?