Isn't this a math problem?
If it is the the answer should be 102.
10 decimeters=1 meter
27x10=270
270-168=102
Hey I tried but could not find your answer, but maybe you could try to calculate the average of bpts of the different elements in the compound to find the boiling point. And when you know the bpt, you can find out whether it is a liquid or gas. But after searching a lot, I found it was a solid. Good luck!
Atomic number = amount of protons, so 7 protons.
Because it is a neutral atom, that means that the number of protons has to be the same as the number of electrons. So, there are 7 electrons.
The mass number of an atom, 15, is the total number of protons + neutrons, so 15 - 7 = 8. There are 8 neutrons
H2Se is the acid as it is donating H+ to H2O and forming SeH- (which is conjugate base).
H2O is the base since it’s receiving H+ from H2Se to form H3O+ (which is the conjugate acid)
Se is in the same group as O but is in different period which means Se has higher radius compred to O. this led to H-O bond being stronger than H-Se bond and H-Se bond which in turn makes it easier for H2Se to donate H to H2O
