Answer:
B. The elements that have similar densities and atomic sizes
Explanation:
Answer:
boron has an atomic mass of 10.810 amu consists of two isotopes.
Answer:
The ΔH is 5.5 kJ/mol and the reaction is endothermic.
Explanation:
To calculate the ∆H (heat of reaction) of the combustion reaction, that is, the heat that accompanies the entire reaction, you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient ( number of molecules of each compound participating in the reaction) and finally subtract them:
Combustion enthalpy = ΔH = ∑H products - ∑Hreactants
In this case:
ΔH = 15.7 kJ/mol - 10.2 kJ/mol= 5.5 kJ/mol
An endothermic reaction is one whose enthalpy value is positive, that is, the system absorbs heat from the environment (ΔH> 0).
<u><em>The ΔH is 5.5 kJ/mol and the reaction is endothermic.</em></u>
Essentially all the available nitrogen for life in the form of nitrates and ammonia would eventually disappear. Nitrogen is needed to make proteins and other chemicals so it is required for all life to exist. It gets recycled so it would take many decades in most places before the available nitrogen ran out. Many crops like beans depend on it. Humans can manufacture it but it would be hard on the ecosystems of the world and eventually probably lead to the extinction of all the ecosystems of the world.
Hope this helps!
