Among common salt sand and copper sulphate , which forms a true solution

                     Common Salt and Copper Sulfate forms a true solution.

Explanation:

                    True Solutions are those solutions in which the solutes are uniformly distributed throughout and forms a homogeneous mixture. In these solutions the solutes either exist in molecular form exist as ions. Like in given cases;

                                 NaCl ₍s₎   →   Na⁺ ₍aq₎  +  Cl⁻ ₍aq₎

and,

                            CuSO₄ ₍s₎   →   Cu²⁺ ₍aq₎  +  SO₄²⁻ ₍aq₎  

Also, the size of solutes in true solutions is less than 1 nm. Also, when allowed for longer time these ions in true solutions never settles down at the bottom. This formation of true solution by these two compounds is mainly due to their greater solubility in water. The ions formed have greater force of interactions with the molecules of eater.

Also, the sand fails to form the true solution because sand in insoluble in water. The force of attractions between the sand and water are smaller than the force of attractions between sand molecules. Thus, when added in water the sand particles precipitates out and settle down at the bottom.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them  

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.