13. earth's surface area is 5.1 x 10^8 km², its crust has an average thickness of 35 km and an average density of 2.8 g/cm'. the two rarest (non-radioactive) elements in the crust are ruthenium and rhodium, each with an abundance of 1.0 x 10g/metric ton crust. what is the total mass of these two elements in the earth's crust? (1g = 1 x 10 metric ton)

Supongamos que estás estudiando dos estrellas. ambas estrellas tienen la misma magnitud aparente, pero la estrella a tiene una magnitud absoluta mayor que la estrella b. ¿que puedes decir acerca de la distancia a la tierra de estas dos estrellas?

In an effort to address concerns about global warming, a power plant in portland,oregon is designed to take all of its exhaust gases from its boilers and recycle the co2 using the solvay process to make sodium hydrogen carbonate. the reaction is shown below. nh3(g) + h2o(l) + co2(g) + nacl(aq) → nahco3(aq) + nh4cl(aq) how many liters each of nh3 and co2 (both at stp) would be consumed to produce 3.00 kg of sodium bicarbonate? the volume of both nh3 and co2 would be

What type of reaction is shown below? check all that apply. 2h2o2 → 2h2o + o2 synthesis decomposition combustion