An atom with a positive charge is an anion.
a. true
b. false

What is the energy in joules of a mole of photons associated with visible light of wavelength 486 nm?

The footprints of a dinosaur and the burrow of an ancient shrimp are examples of which kind of fossils

Which of the following reactions represents an exothermic reaction? nh3(g) + 12.0 kcal ½n2(g) + 3/2 h2(g) ch4 + 2o2 co2 + 2h2o + 212,800 cal c + 2s cs2, h = 27,550 cal c(graphite) c(diamond), h = 0.45 kcal 2h2o 2h2 + o2, h = +58 kcal