Density = mass/volume = 800/200 =4 g/cm^3
Answer:
CaCl2 + H2O Ca2+(aq) + 2Cl-(aq)
Explanation:
CaCl2 + H2O Ca2+(aq) + 2Cl-(aq)
When CaCl2 is dissolved in H2O (water) it will dissociate (dissolve) into Ca+2 and Cl- ions.
The dissolution of calcium chloride is an exothermic process.
Answer:
7 to 4 (higher
)
5 to 3
3 to 2
4 to 2 (lower
)
Explanation:
We can use the Rydberg formula which relates the wavelength of the photon emissions to the principle quantum numbers involved in the transition:

with
final n, and
initial n
evaluating for each transition:
7 to 4 
5 to 3 
4 to 2 
3 to 2 
Note that the above formula is written for
, so lower
value obtained involves higher
.
So we should order from lower to higher 
7 to 4 (higher
)
5 to 3
3 to 2
4 to 2 (lower
)
Note: Take into account that longer wavelength involves lower energy (
).
1. Oil
2. Petroleum
Hope this helps