Question

Lesson 02.03: Isotopes and Weighted Averages
• Identify the differences between isotopes of an element.
• Calculate the weighted average mass of an element when given the percent abundance and mass of its isotopes.


Lesson 02.04: The Mole and Conversions
• Describe the mole and its use in chemistry calculations.
• Use the mole, Avogadro’s number, and molar mass in dimensional analysis calculations.

Answer 1

The Mole and Conversions
A mol is nothing but a number. We use it to describe how many molecules we are dealing with. So we I for example say I got 1 mol of molecules in my hand I say in orders I got about 602 trillion molecules in my hand.

The mole, Avogadro’s number, and molar mass:
Molar mass:
\[\large M=\frac{ m }{ n }\]
M is the molar mass [g/mol]
m is the max [g]
n amount of substance [mol]
The about of substance n is given by:
\[\large n=\frac{ N }{ N _{A} }\]
N is the amount of molecules.
Na Avogadro's constant.
1 g = 1 Na * u (per definiton)
u is the unit "unit" (Atomic mass unit)

Answer 2

or is 1 gram redefined by now @abb0t ?

Answer 3

What are you talking about?

Answer 4

The conventions between atomic mass units, gram and Avogadro's constant. Know that some have been talking about to determine Avogadro's constant so accurate that it should replace the standard gram weight.