Solution:
The idea of an atom proposed by the Greek philosophers because:
According to Greek Philosopher, matter is composed of small and indivisible particles called atoms. He introduced atoms as too small to be seen, unchangeable, completely solid without internal structure. He proposed that atoms are of variety of shapes and sizes which is responsible for different types of matter.
But according to Dalton’s atomic theory, chemical elements have atoms, which are identical in weight. The different elements have different atoms of different weight. Atoms can combine in whole-number ratios to form compounds. These observations are already introduced by Greek philosopher, but the idea of atomic weight is introduced by Dalton. He introduced the list of 21 elements with their atomic weights and, he was the first to propose the element’s symbol.
Answer:
1.63ₓ10⁻⁶ g of U
139.03 g of H
0.385 g of O
141.8 g of Pb
Explanation:
In first place, we need to convert the number of atoms to moles, as we know that 1 mol of anything occupies 6.02×10²³ particles
Therefore:
4.12×10¹⁵ atoms of U . 1 mol / 6.02×10²³ atoms = 6.84×10⁻⁹ moles of U
8.37×10²⁵ atoms of H . 1 mol /6.02×10²³ atoms = 139.03 moles of H
1.45×10²² atoms of O . 1 mol /6.02×10²³ atoms = 0.0241 moles of O
4.12×10²³ atoms of Pb . 1 mol /6.02×10²³ atoms = 0.684 moles of Pb
Moles . Molar mass = Mass (g)
6.84×10⁻⁹ moles of U . 238.03 g/mol = 1.63ₓ10⁻⁶ g of U
139.03 moles of H . 1 g/mol = 139.03 g of H
0.0241 moles of O . 16 g/mol = 0.385 g of O
0.684 moles of Pb . 207.2 g/mol = 141.8 g of Pb
Answer:

Explanation:
Hello,
Considering the ideal equation of state:

The moles are defined in terms of mass as follows:

Whereas
the gas' molar mass, thus:

Now, since the density is defined as the quotient between the mass and the volume, we get:

Solving for
:

Thus, the result is given by:
![density=\frac{(1atm)(44g/mol)}{[0.082atm*L/(mol*K)]*298.15K} \\density=1.8g/L=1.8x10^{-3}g/mL](https://tex.z-dn.net/?f=density%3D%5Cfrac%7B%281atm%29%2844g%2Fmol%29%7D%7B%5B0.082atm%2AL%2F%28mol%2AK%29%5D%2A298.15K%7D%20%5C%5Cdensity%3D1.8g%2FL%3D1.8x10%5E%7B-3%7Dg%2FmL)
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