Answer:NASA's Lunar Atmosphere and Dust Environment probe, for instance, orbits the moon and collects information about its atmosphere and surface. This important data can help scientists learn more about moons, asteroids and other objects in the solar system.
Explanation:
<span>There are pros and cons as to whether CCA-treated (pressure-treated) wood should be removed from existing structures, and both sides are subjective.
Some of the arguments for leaving it include:
*When burned, the wood can release dangerous, and sometimes, lethal fumes.
*If buried in a landfill, the chemicals can soak into the ground and eventually contaminate ground water.
*Removing it can expose people to arsenic
*It is costly to remove an existing infrastructure that may or may not be harming people
*Studies conducted within the past decade have determined structures containing CCA-treated wood pose no hazard
*Studies also concluded that children who played on CCA-treated playgrounds were exposed to arsenic levels lower than those that naturally occur in drinking water
Some of the arguments for removing it include:
*The EPA determined that some children could face higher cancer risks from exposure to CCA-treated wood
*If removed, it will need to be disposed of and, as discussed above, that creates another set of problems that could affect a community's health.
A possible solution is to leave existing CCA-treated wood in place but seek viable, safe alternatives for future structures.</span>
Explanation: just add the atomic masses on the periodic table together for each atom.
Answer:
Las siguientes son reacciones químicas;
combustión de leña
oxidación del hierro
descomposición del agua en hidrógeno y oxígeno
Explanation:
Una reacción química da como resultado la formación de una (s) sustancia (s) nueva (s), mientras que un cambio físico no conduce a la formación de una sustancia nueva.
Las siguientes son reacciones químicas;
combustión de leña: la combustión de madera implica la oxidación del carbono según la reacción; C (s) + O2 (g) -------> CO2 (g)
oxidación del hierro: La oxidación del hierro conduce a la formación de óxidos de hierro. Como; 2Fe (s) + O2 (g) ----> 2FeO (s)
descomposición del agua en hidrógeno y oxígeno: esta es una reacción química en la que el agua se descompone de la siguiente manera; 2H2O (l) -----> 2H2 (g) + O2 (g)
Todos estos procesos enumerados anteriormente conducen a la formación de nuevas sustancias, por lo tanto, son reacciones químicas.
Answer:
131.5 kJ
Explanation:
Let's consider the following reaction.
CaCO₃(s) → CaO(s) + CO₂(g)
First, we will calculate the standard enthalpy of the reaction (ΔH°).
ΔH° = 1 mol × ΔH°f(CaO(s)) + 1 mol × ΔH°f(CO₂(g)
) - 1 mol × ΔH°f(CaCO₃(s)
)
ΔH° = 1 mol × (-634.9 kJ/mol) + 1 mol × (-393.5 kJ/mol) - 1 mol × (-1207.6 kJ/mol)
ΔH° = 179.2 kJ
Then, we calculate the standard entropy of the reaction (ΔS°).
ΔS° = 1 mol × S°(CaO(s)) + 1 mol × S°(CO₂(g)
) - 1 mol × S°(CaCO₃(s)
)
ΔS° = 1 mol × (38.1 J/mol.K) + 1 mol × (213.8 J/mol.K) - 1 mol × (91.7 J/mol.K)
ΔS° = 160.2 J/K = 0.1602 kJ/K
Finally, we calculate the standard Gibbs free energy of the reaction at T = 25°C = 298 K.
ΔG° = ΔH° - T × ΔS°
ΔG° = 179.2 kJ - 298 K × 0.1602 kJ/K
ΔG° = 131.5 kJ
