Answer: the atomic number 7 is
Nitrogen
Explanation:
Answer:
Other forms of energy can convert to mechanical energy
Explanation:
For example the electric or magnetic energy in a motor can convert to mechanical energy, or another example is when you put two magnets together they will clip together due to the magnetic energy that they have.
1) Carbon dioxide is a gas, so when
is evolved in the reaction, it appears as bubbles. The gas released extinguishes the fire and it can turn lime water milky.

2) When
is released in a decomposition reaction we can identify by the strong pungent smell of the gas released.
3) Saturated citric acid can cause corrosion of the metal layers present in the pipes. So, before draining out any acid it is neutralized so that the pipes and other plumbing works do not get damaged leading to leaks in the drainage system.
Co2
Explanation:
CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (l)
Answer:
ΔH =
Explanation:
In a calorimeter, when there is a complete combustion within the calorimeter, the heat given off in the combustion is used to raise the thermal energy of the water and the calorimeter.
The heat transfer is represented by
= 
where
= the internal heat gained by the whole calorimeter mass system, which is the water, as well as the calorimeter itself.
= the heat of combustion
Also, we know that the total heat change of the any system is
ΔH = ΔQ + ΔW
where
ΔH = the total heat absorbed by the system
ΔQ = the internal heat absorbed by the system which in this case is 
ΔW = work done on the system due to a change in volume. Since the volume of the calorimeter system does not change, then ΔW = 0
substituting into the heat change equation
ΔH =
+ 0
==> ΔH =