The graph is missing, however we can answer anyway.
In fact, this is the approximate percentage of the elements listed in the questions in the Earth's crust (data taken from wikipedia):
Iron 5.0 %
Calcium 3.6 %
Sodium 2.8 %
Potassium 2.6 %
Magnesium 1.5 %
of all of these, we see that the combination of two elements that makes up the closest number to 7% is calcium and sodium (3.6% + 2.8%=6.4%), therefore the correct answer is
Calcium and sodium.
for this we apply, Heisenberg's uncertainty principle.
it states that physical variables like position and momentum, can never simultaneously know both variables at the same moment.
the formula is,
Δp * Δx = h/4π
m(e).Δv * Δx = h/4π
by rearranging,
Δx = h / 4π * m(e).Δv
Δx = (6.63*10^-34) / 4 * 3.142 * 9.11*10^-31 * 5.10*10^-2
Δx = 6.63*10^-34 / 583.9 X 10 ⁻³¹
Δx = 0.011 X 10⁻³
for the bullet
Δx = (6.63*10^-34) / 4 * 3.142 * 0.032*10^-31 * 5.10*10^-2
Δx = 6.63*10^-34 /2.05
Δx =3.23 X 10⁻³² m
therefore, we can say that the lower limits are 0.011 X 10⁻³ m for the electron and 3.23 X 10⁻³² m for the bullet
To know more about bullet problem,
brainly.com/question/21150302
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Stars form from an accumulation of gas and dust, which collapses due to gravity and starts to form stars. Stars are typically classified by their spectrum in what is known as the Morgan-Keenan or MK system.
