5 moles of H2
..............
From mole ratios, the mass ratio of different elements can be predicted. Also the volume can be predicted based on density for liquids and ideal gas law equation for gases. From the mole ratios, the empirical formula can be predicted, as well as the molecular formula given another data which is mass of the sample.
Solar energy will not run out (unless the sun burns out), but the supply of fossil fuels we use is slowly depleting. Burning fossil fuel also releases greenhouse gas into the air, which is bad for the atmosphere.
Answer:
The entropy and the systems surrounding it tend to increase.
Answer:
Density of unit cell ( rhodium) = 12.279 g/cm³
Explanation:
Given that:
The radius (r) of a rhodium atom = 135 pm
The atomic mass of rhodium = 102.90 amu
For a face-centered cubic unit cell,

where;
a = edge length.
Making "a" the subject of the formula:


a = 381.8 pm
to cm, we get:
a = 381.8 × 10⁻¹⁰ cm
However, recall that:
where;
mass of unit cell = mass of atom × numbers of atoms per unit cell
Also;


Recall also that number of atoms in a unit cell for a face-centered cubic = 4
So;

mass of unit cell = 6.83380375 × 10⁻²² g

Density of unit cell ( rhodium) = 12.279 g/cm³