Carbon dating of small bits of charcoal used in cave paintings has determined some of the paintings are from 10,000 to 30,000 years old. Carbon 14 has a half life of 5730 years. In a 1-μg sample of carbon from a living tree, the activity of carbon-14 is 6.4 6.4 μCi. If researchers determined that 1 μg of charcoal from a prehistoric cave painting in France has an activity of 0.80 μCi, what is the age of the painting?

The combustion of methane, ch4, releases 890.4kj/mol. that is, when one mole of methane is burned,890.4 kj are given off to the surroundings. this meansthat the products have 890.4 kj less than the reactants.thus, ah for the reaction = - 890.4 kj. a negative symbolforah indicates an exothermic reaction.ch (g) + 20 (g)> co2 (g) + 2 h0 (1); ah = - 890.4 kga) how much energy is given off when 2.00 mol of ch,are burned? b) how much energy is released when 22.4g of ch. areburned?