Answer: 
Explanation:
When a number is written in scientific notation (representing the number using powers of base ten) it is expressed so that it contains a digit in the place of the units and all other digits after the decimal point, multiplied by the respective exponent.
Then, the significant figures (or significant digits) will be the digits that are before the power of ten.
Now, in the case of the number 299,792,458 if we want to write it with three significant digits, we have to write it in scientific notation as:

B. Frequency remains unchanged because the energy in a photon is E=hf. So if the frequency changes so does the energy and that doesn't happen to EM waves entering a medium by the conservation of energy
Answer:
λ = 3.1824 10-25 m
Explanation:
To release the electron from the power well the absorbed photon electro must be greater than or equal to the energy of the electron in the power well
The photon energy is E_photon = 0.625 J
The speed of light is
c = λ f
Let's use Planck's equation
E = h f
We substitute
E = h c / λ
λ = h c / E
λ = 6.63 10-34 3 108 / 0.625
λ = 3.1824 10-25 m
The type of graph that would most appropriately display Sarah's data is a line graph.
<h3>What is a line graph?</h3>
A line graph, sometimes referred to as a line plot or a line chart, is a graph in which individual data points are connected by lines. A line graph shows numerical values over a predetermined period of time.
Line graphs are frequently used in finance to show the historical price movement of an asset or instrument. To monitor changes over both short and long time periods, line graphs are utilized. Line graphs can be used to compare changes for multiple groups over the same time period.
In this case, it should be noted that Sarah wants to compare the speed and the height. Therefore, the line graph and s appropriate.
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