A covalent bond doesn't give rise to ions. A coordinate covalent (or Dative) bond is similar to a covalent bond and the only difference is that in a Dative bond, the shared pair of electrons is contributed by only one of the atoms. But in the reactions, I notice some ions formed. For example: in formation of hydroxonium, H3O+ : O2 + H+ = H3O+ Please I need to be clarified

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.

a physical change biology

explanation: