Zinc metal; copper (ii) sulfate solution
(a) molecular equation:
(b) total ionic equation:
(c) net ionic equation:

A =Zn(s) + CuSO₄ (aq)    →    ZnSO₄ (aq)  + Cu (s)

B = Zn(s) + Cu²⁺(aq) + SO₄²⁻ (aq)    →    Zn²⁺(aq) + SO₄²⁻(aq)  + Cu(s)

C = Zn(s) + Cu²⁺(aq)    →    Zn²⁺  (aq) + Cu(s)

Explanation:

The reactivity of zinc is higher than than copper. That's why when zinc is added into the copper(ii) sulfate it displace the copper and form zinc sulfate solution.

Molecular equation:

Zn(s) + CuSO₄ (aq)    →    ZnSO₄ (aq) + Cu(s)

It is redox reaction. The copper is reduced because its oxidation number reduced from +2 to zero and zinc is oxidize its oxidation state increase from zero to +2.

Ionic equation:

Zn(s) + Cu²⁺(aq) + SO₄²⁻ (aq)    →    Zn²⁺(aq) + SO₄²⁻(aq)  + Cu(s)

Net ionic equation:

Zn(s) + Cu²⁺(aq)    →    Zn²⁺  (aq) + Cu(s)

The  SO₄²⁻ are spectator ions that's why these are not written in net ionic equation.

Spectator ions:

These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.  

specific gravity is the density of a substance divided by the density of water. since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density

so "c" is the answer

plz give brainliest

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.