Answer:
Francium is hypothesized to be the most reactive metal, but so little of it exists or can be synthesized, and the longest half-life of its most abundant isotope is
22.00
minutes, so that its reactivity cannot be determined experimentally.
Explanation:
Francium is an alkali metal in group 1/IA. All alkali metals have one valence electron. As you go down the group, the number of electron energy levels increases – lithium has two, sodium has three, etc..., as indicated by the period number. The result is that the outermost electron gets further from the nucleus. The attraction from the positive nucleus to the negative electron is less. This makes it easier to remove the electron and makes the atom more reactive.
Experimentally speaking, cesium (caesium) is the most reactive metal.
1 moles -------- 6.02x10²³ atoms
?? moles ----- 7.4x10²¹ atoms
moles = 7.4x10²¹ / 6.02x10²³
= 0.01229 moles
hope this helps!
Since the scientists found a fossil from a modern day badger from the Holocene geologic epoch, the badger would be mostly the same, as this is the most recent, and still on going geologic epoch, starting from little less than 12,000 years ago. If the scientist wants to find a fossilized remains of earlier badgers, thus of their ancestors from the Pleistocene epoch, than the scientist should dig deeper. Not a lot deeper though, as the layers of rock from the Pleistocene are just bellow the layers of rock from the Holocene, as the Pleistocene is the second youngest geologic epoch, being the predecessor of the Holocene.
C. the square root of 2gh
Explanation:
The square root of 2gh is equivalent to Torricelli's law in the equation.
given expression:
m v² = mgh
to find v, we make it the subject of the expression:
*multiply both sides of the equation by 2:
2 x( m v² )= 2 (mgh)
mv² = 2mgh
*cancel the mass, m appearing on both sides:
v² = 2gh
* find the square root of both side
v = √2gh
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Answer : Total molecules that will be needed to visualize a single egg will be 78500 molecules of dye.
Explanation : As a single egg cell has an approximately diameter of 100 μm.
We can use this formula to calculate area of the cell membrane;
A = π 
;
We can take π as 3.14 and we get;
A = 3.14 X
Soving we get;
A = 7850 μ
Here we have to calculate the amount of dye molecules which will be needed for 10 fluorescent molecules / μ but;
here 1 μ = 7850 μ dye molecules.
Therefore, 10 fluorescent molecules will need;
7850 X 10 = 78500 molecules of dye.
Therefore, the answer is 78500 molecules of dye.
