Atomic mass of helium is 4.002642g/mol
(542000g)/(4.002642g/mol)*6.02*10^23 = 8.15*10^28 atoms
Answer:
Hydrogen and Chlorine
Explanation:
They are both an example in univalent atoms, because of their nature to form only one single bond.
I wasn't able to find another example, hope it helped! :)
Answer:
migratory distribution
Explanation: The pattern of migratory distribution of species may require collaboration between different countries for effective preservation. This is because species migration can make them enter different territories, which will need to provide an effective level of preservation for species survival
Answer:
4.186 L
Explanation:
Using the pv=nrt equation and converting the grams of O2 into mols. After finding the number of mols by dividing 5.98 by 32 (2*the atomic weight of O) you plug that into the equation. So then you have 1*V=.186875*.08206*273 then you rearrange the equation to solve for v and get 4.186 L
Answer: A. -396 kJ
Explanation:
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
Reversing the reaction, changes the sign of 
On multiplying the reaction by 2, enthalpy gets multiplied by 2:
Thus the enthalpy change for the reaction is -396 kJ.
