Based on the enthalpy changes given for the reactions, which reactions are endothermic? (check all that apply) 2h2o → 2h2 + o2, δh = 484 kj c + o2 → co2, δh = -394 kj h2 + br2 → 2hbr, δh = -73 kj 2nh3 → n2 + 3h2, δh = 92 kj

What is avogadro’s number, and why is it useful

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole

There are 6.022, 104 atoms of hg in 1 mole of hg the number of atoms in 45 moles of hg can be found by multiplying 4.5 by 6.022, 102 which is the number of atoms in 4.5 moles of hg, correctly written in scientific notation with the correct number of significant figures? 0 21,109 0 21,100 271, 1024 27.099, 100 mark this and retum save and exit submit