The atomic number of the atom is 13. This means that its electronic configuration is (2 8 3) or in other words:
1<span>s2, </span>2<span>s2, </span>2<span>p6, </span>3<span>s2, </span>3<span>p<span>1
If three electrons are lost, then these electrons are removed from the outermost level.
In our case, electrons are removed from the third energy level (one electron is removed from the 3p orbital and two electrons are removed from the 3s orbital).</span></span>
Explanation:
For this problem, use the first law of thermodynamics. The change in energy equals the increase in heat energy minus the work done.
ΔU=Q−W
We are not given a value for work, but we can solve for it using the force and distance. Work is the product of force and displacement.
W=FΔx
W=3N×2m
W=6J
Now that we have the value of work done and the value for heat added, we can solve for the total change in energy.
ΔU=Q−W
ΔU=10J−6J
ΔU=4J
Answer is 4J
i think this may help you very much
Answer:ans is b solids
Explanation: this is because molecules in a solid medium re much closer together than those in liquid or gas allowing sound waves to travel quickly through it
Answer:
the wavelength λ of the light when it is traveling in air = 560 nm
the smallest thickness t of the air film = 140 nm
Explanation:
From the question; the path difference is Δx = 2t (since the condition of the phase difference in the maxima and minima gets interchanged)
Now for constructive interference;
Δx= 
replacing ;
Δx = 2t ; we have:
2t = 
Given that thickness t = 700 nm
Then
2× 700 =
--- equation (1)
For thickness t = 980 nm that is next to constructive interference
2× 980 =
----- equation (2)
Equating the difference of equation (2) and equation (1); we have:'
λ = (2 × 980) - ( 2× 700 )
λ = 1960 - 1400
λ = 560 nm
Thus; the wavelength λ of the light when it is traveling in air = 560 nm
b)
For the smallest thickness 
∴ 



Thus, the smallest thickness t of the air film = 140 nm
I think the correct answer is C. Volcanoes are formed in subduction zones or in rift valleys. They are formed when hot magma within the upper mantle of the Earth would work way up the surface. As it reaches the surface, an eruption would happen forming lava flows and deposits of ash. As it continues to erupt, it would grow bigger and bigger. These would form commonly in divergence or convergence tectonic plates. On Earth, there are about 1500 volcanoes that are active. About 80 of these can be found under the oceans. The active ones are mostly found in washington, oregon, alaska, california and hawaii.