Answer:
See the answer below.
Explanation:
The latent heat of fusion is defined as the amount of energy needed to make a phase change from solid to liquid. And it can be calculated by means of the following expression:
where:
Qfusion = Heat Energy [J]
m = mass = 0.65 [kg]
Dh = latent heat fusion = 330000[J/kg]
![Q_{fusion}=0.65*330000\\Q_{fusion}=214500[J]](https://tex.z-dn.net/?f=Q_%7Bfusion%7D%3D0.65%2A330000%5C%5CQ_%7Bfusion%7D%3D214500%5BJ%5D)
2)
We know that energy can be calculated from power, where power is defined as the relationship between energy over time.
where:
P = power = 60 [w]
E = energy [J]
t = time = 5 [min] = 300 [s]
![E=P*t\\E=50*300\\E=15000[J]](https://tex.z-dn.net/?f=E%3DP%2At%5C%5CE%3D50%2A300%5C%5CE%3D15000%5BJ%5D)
The mass change due to the process is equal to:
![m=282-274\\m=8[g]=0.008[kg]](https://tex.z-dn.net/?f=m%3D282-274%5C%5Cm%3D8%5Bg%5D%3D0.008%5Bkg%5D)
Now using the following equation for the latent heat of Fusion, we can calculate this value:
![Q=m*Dh\\Dh =Q/m\\Dh=15000/0.008\\Dh=1875000[J/kg]](https://tex.z-dn.net/?f=Q%3Dm%2ADh%5C%5CDh%20%3DQ%2Fm%5C%5CDh%3D15000%2F0.008%5C%5CDh%3D1875000%5BJ%2Fkg%5D)
Answer:
The electronic transition of an electron back to a lower energy level generates an emission spectrum.
Explanation:
The atomic emission spectrum¹ of an element has its origin when an electronic transition² occurs. An electron in an atom or ion³will absorb energy coming from a source and pass to a higher energy level, the electron, upon returning to its base state will emit a photon⁴ or a series of photons.
Hence, that leads to the formation of an emission spectrum.
Remember that an electron has energy levels in an atom or ion, at which each energy level has a specific value.
The energy values will differ from one element to another. So, it can be concluded that each element has a unique pattern of emission lines.
Key terms:
¹Spectrum: Decomposition of light in its characteristic colors.
²Electronic transition: When an electron passes from one energy level to another, either for the emission or absorption of a photon.
³Ion: An atom electrically charged due to the gain or loss of electrons.
⁴Photon: Elementary particle that constitutes light.
The law of conservation of energy states that energy is neither created nor destroyed; the amount remains constant. For example, a form of energy-thermal energy, or heat, occurs by convection or conduction
