Answer:
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Answer:
The set of frequencies of the electromagnetic Waves emitted by the atoms of an element is called emission spectrum.
Answer:
The correct answer is 
Explanation:
The formula for the electron drift speed is given as follows,

where n is the number of of electrons per unit m³, q is the charge on an electron and A is the cross-sectional area of the copper wire and I is the current. We see that we already have A , q and I. The only thing left to calculate is the electron density n that is the number of electrons per unit volume.
Using the information provided in the question we can see that the number of moles of copper atoms in a cm³ of volume of the conductor is
. Converting this number to m³ using very elementary unit conversion we get
. If we multiply this number by the Avagardo number which is the number of atoms per mol of any gas , we get the number of atoms per m³ which in this case is equal to the number of electron per m³ because one electron per atom of copper contribute to the current. So we get,

if we convert the area from mm³ to m³ we get
.So now that we have n, we plug in all the values of A ,I ,q and n into the main equation to obtain,

which is our final answer.
By definition, the law of conservation of energy states that:
Ei = Ef
Where,
Ei: initial energy
Ef: final energy
Therefore, no matter the type of energy, always the final energy is equal to the final energy.
Energy can be transformed into another type of energy. For example, the potential energy can be transformed into kinetic energy.
Also, energy is not created, nor destroyed.
Answer:
The following is not true about the Law of Conservation of Energy:
A. It states that the total energy in the universe keeps increasing.
Answer:multiplying will give us 7 significant figures and addition will give us 3 significant figures
Explanation:
After multiplying the two numbers they resulting value will give a value in its 4 decimal places because both given values are in 2 decimal places. The 4 dp is gotten by the addition of the decimal places of both given numbers (2+2) and
The result of its addition will give us a value in its 1dp and 3 significant figures since the addition of 23.68 and 4.12 will give us 27.8