Answer:
Explanation:
We can only talk about resonance hybrid for a compound in which more than one structure is possible based on its observed chemical properties.
There are compounds whose chemical properties can not be satisfactorily explained on the basis of a single chemical structure. In the case of such compounds, we invoke the idea of resonance.
A resonance hybrid is a single structure drawn to represent a given chemical specie which exhibits resonance behaviour and can otherwise be represented on paper in the form of an average of two or more chemical structures separated each from the next by a double-headed arrow.
If copper is heated with iron oxide there is no obvious reaction because
copper is less reactive than iron.
On a reactivity chart, copper is far below iron. This makes it impossible for a replacement reaction to occur, so the equation doesn't change.
I hope I helped!
Explanation:
Since, density is the amount of mass present in per unit volume.
Mathematically, Density = 
As density is directly proportional to mass of a substance. So, more is the density of a substance more will be its mass. And, when more is the mass of a substance then it is likely to sink at the bottom.
Here, it is given that density of oxygen is more than the density of nitrogen. Therefore, balloons filled with oxygen will sink in the air.
On the other hand, balloons filled with nitrogen will rise in the air.
The molar mass of copper is 63.55 g/mol. So, you convert grams to moles 127.08/63.55 =1.999 moles copper. Now, 1 mole = 6.022e23 atoms, so multiply # of moles by 6.022e23. 1.999 x 6.022e23= # of atoms of copper.
