The fourth (last) one in 2-8-8-2.
From the periodic table:
molecular mass of carbon = 12 grams
molecular mass of fluorine = 18.99 grams
molecular mass of chlorine = 35.5 grams
Therefore:
one mole of CF2Cl2 = 12 + 2(18.99) + 2(35.5) = 120.98 grams
Therefore, we can use cross multiplication to find the number of moles in 79.34 grams as follows:
mass = (79.34 x 1) / 120.98 = 0.6558 moles
Now, one mole contains 6.022 x 10^23 molecules, therefore:
number of molecules in 0.65548 moles = 0.6558 x 6.022 x 10^23
= 3.949 x 10^23 molecules
I believe the most massive element that is naturally occurring on Earth is uranium (U), which has a nucleus of 92 protons
Ernest Rutherford's gold-foil experiment showed the density of atoms.
<span>The experiment proved that most of an atom is empty space with a very small positively charged nucleus in the middle.
So, from the given statements he following is true:
</span><span>Ernest Rutherford's gold-foil experiment showed </span>the existence of a dense, positively charged center in an atom.
