Which of the following metals or nonmetals are expected to displace Mn or Cl (respectively) from MnCl2? 1. Cu should displace Mn. 2. Ca should displace Mn. 3. Br should displace Cl. 4. I should displace Cl.

. Ca should displace Mn

Explanation:

Calcium is high up in the activity series of metals. Calcium has a very negative redox potential of -2.87 V, next only to potassium. Transition metals of which Manganese is one, does not have such very negative redox potentials so they can easily be displaced by a more highly reactive metal such as Calcium. Elements of group 1 and 2 are very highly reactive.

answer; i believe the correct answer is (solid gold);

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.