HELP ASAP PLEASE, CAN SOMEONE LITERALLY JUST TELL ME IF THIS EXPLANATION IS CORRECT AND IF IT MAKES SENSE, ESPECIALLY THE LAST PART. DON'T DO IT FOR THE POINT I GENUINELY NEED HELP. This is what happens when H2O (water) and KCl (Salt, potassium chloride) are mixed: first, we have to be aware that H2O is held together by a covalent bond because both atoms are nonmetals, they're sharing electrons in order to fulfill the octet rule. But in the case of H, since it is on period 1, it only has one shell, so that will count as its valence shell and only 2 electrons fit, only 2 electrons are needed for Hydrogen to be stable/“happy”. It is a very peculiar molecule due to its polarity, one side is negatively charged and the other one is positively charged. This happens because Oxygen’s electronegativity (3.5), making the partially negative side of the Molecule, and Hydrogen is less electronegative (2.1), making it the slightly positive side of the water molecule/less negative. The two Hydrogens make up the positive side, therefore, it'll attract negatively charged ions, and Oxygen is the negative side, therefore, it'll attract positively charged ions. The other substance is KCl which is held together by an ionic bond which means the electrons are not being shared by the two atoms like in a covalent bond. Chlorine's strong electronegativity pulled one electron from Potassium leaving us with two separate ions. Since electrons have a negative charge, Potassium who lost one will turn into a cation(+), and Chlorine will turn into an anion(-). Now when H2O is mixed with KCl, the ionic bond or the attraction (called electrostatic attraction) that holds it together is broken, that's why the temperature decreases. This happens because the process of breaking the bonds, requires a lot of energy from atoms, and since energy is used during this process, there’s less energy in the molecules, and that leads the temperature to decrease. Then H2O's polarity pulls the ions accordingly, the positive side (Hydrogen) attracts Chlorine (Cl-), and the negative side (Oxygen) attracts Potassium (K+), in other words, KCl (salt) dissolves in H2O (water). A chemical reaction is when the reactants, which is the starting substances added together, in this case salt and water; result into different substances called reactants. In my opinion, adding salt and water is not a chemical reaction because the changes can be reversed, not by chemical reaction but a physical change (exposure to heat), and after all they're still water and salt.