ITS FOR AN EXAM GUYS PLEASE What are the half-reactions for a galvanic cell with aluminum and gold
electrodes?

A. and

Explanation:

Galvanic cell is a device which is used for the conversion of the chemical energy produces in a redox reaction into the electrical energy.

The standard reduction potential for aluminium and gold are as follows:

Reduction takes place easily if the standard reduction potential is higher (positive) and oxidation takes place easily if the standard reduction potential is less (more negative).

Here Al undergoes oxidation by loss of electrons, thus act as anode. Gold undergoes reduction by gain of electrons and thus act as cathode.

Anode :

Cathode :

Thus magnesium gets oxidized.

i believe it is a.) released into

explanation:

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.