Select the correct answer. What is the reason for heat transfer from one substance to another

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

4.25g sample of solid ammonium nitrate dissolves in 60.0g of water in a coffee-cup calorimeter, the temperature drops from 22.0 c to 16.9 c. assume that the specific heat of the solution is the same as that of pure water. calculate delta(h) (in kj/mol nh4no3) for the solution proces.

The image compares the arrangement of electrons in two different neutral atoms. a figure labeled atom q has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has six black spheres. to the left of this figure is another figure labeled atom p. atom p has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has seven black spheres. which of the following best explains the position of the two atoms in the periodic table? atom p has an estimated zeff of 7 and is therefore to the left of atom q, which has a zeff of 6. atom p has an estimated zeff of 7 and is therefore to the right of atom q, which has a zeff of 6. atom p has an estimated zeff of 5 and is therefore below atom q, which has a zeff of 4. atom p has an estimated zeff of 5 and is therefore above atom q, which has a zeff of 4.