1) Frequency: 
the energy of the photon absorbed must be equal to the ionization enegy of the atom, which is
The energy of a photon is given by
where 
is the Planck's constant. By using the energy written above and by re-arranging thsi formula, we can calculate the frequency of the photon:
2) Wavelength: 91.2 nm
The wavelength of the photon can be found from its frequency, by using the following relationship:
where 
is the speed of light and f is the frequency. Substituting the frequency, we find
The decimal point is placed after two digits starting from the end. For each decimal place, we can write the number divided by 100.
21.12 can be written as 
.
Divide the numerator and denominator by 2:
The numerator and denominator can be divided by 2 again:
There is no other common factor between numerator and denominator other than 1. Hence, it is the reduced form.
Answer:
State A = piece of metal; State B = air
Explanation:
For the three main states of matter here's how it breaks down.
Solid - Cannot be compressed and retains its shape
Liquid - Cannot be compressed and does not retain its shape
Gas - Compressible and does not retain its shape.
Knowing this State A has to be solid. Only one of the options has A as a solid, so that's the answer. Worth knowing state B is a gas though, only one compressible, just like solid is the only one that retains its shape.
Answer:
Wilhelm Conrad Roentgen (1845-1923)
Antoine Henri Becquerel (1852-1908)
Pierre (1859-1906) and Marie (1867-1934) Curie
Explanation:
Wilhelm Conrad Roentgen (1845-1923)
Contribution: Discovery of x-rays in 1901.
Antoine Henri Becquerel (1852-1908)
Contribution: He discovered that radioactivity is the separation of x-rays and document and the difference between two.
Pierre (1859-1906) and Marie (1867-1934) Curie
Contribution: She discovered Polonium and Radium in1911
From the calculation, the value of the acceleration is 5.8 m/s^2.
<h3>What is uniform acceleration?</h3>
The term uniform acceleration refers to a situation in which the velocity increases by equal amounts in equal time intervals.
Given the fact that the car started from rest and reached a velocity of 780.34 mph or 348.84 m/s in 1 minute of 60 seconds;
v = u + at
a = v/t
a = 348.84 m/s/ 60 seconds
a = 5.8 m/s^2
Learn more about acceleration:brainly.com/question/12550364?
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