This is more of a physics explanation, but here we go.
Mass is a measure of how much "matter" is in an object. Weight is the force applied onto an object by gravity. Weight itself can be related to mass like this:

where g is a gravitational constant. For our purposes, it's defined by whatever planet you are on. Following this, we can demonstrate that mass is NOT the same thing as weight if we take two objects of the same mass and put them on different planets.
Let E refer to Earth and F refer to Mars

Following this, we can see clearly that weight is not the same as mass:

If weight was the same thing as mass, the two values would be the same, as the mass of the two objects is the same. But since weight is defined in the context of gravity, they are not.
If 0.5 L of solution contains 4 mol
then let 1 L of solution contain x mol
⇒ (0.5 L) x = (4 mol) (1 L)
x = (4 mol · L) ÷ (0.5 L)
x = 8 mol
Thus the molarity of the Sodium Chloride solution is 8 mol / L OR 8 mol/dm³.
.8 grams of phosphorus are recommended.
Given :
10 gram sample of propane( C₂H₈ ).
To Find :
The number of moles of propane in given sample.
Solution :
Molecular mass of propane, M = (2 × 12) + ( 1 × 8 ) gram/mol
M = 32 gram/mol
We know, number of moles is given by :
Number of moles, n = m/M
n = 10/32 mol
n = 0.3125 mol
Therefore, number of moles in given sample is 0.3125 mol.
Answer:
407pm is the edge length of the cubic unit cell
Explanation:
In a Face-centered cubic unit you can use Pythagoras theorem to relate edge length with atomic radius (As you can see in the picture), thus:
e²+e² = (4r)²
2e² = 16r²
e = √8 r
If the atomic radius of the atom is 144pm:
e = √8 ×144pm
e = 407ppm
407pm is the edge length of the cubic unit cell