In high school physics, you might be posed the following question:<\/p>\n
How many moles of electrons in a Coulomb?<\/p>\n
If you’re familiar with the concepts involved, the answer is not difficult.
\n6.24e18electrons\/Coulomb*1mole\/6.02e23electrons =6.24e18mole\/6.02e23Coulomb<\/p>\n
=1.04e-5 moles\/Coulomb<\/p>\n
However, to approach the problem, you need to know the constants 6.24e18 and 6.02e23, or else have them handy.<\/p>\n
As a student, I soon memorized those constants. Before I had, I needed a reference table, which is often found in the cover of a textbook.<\/p>\n
Now, you can use a calculator that has built-in constants. Today I’m highlighting the SHARP EL-520W. To get Avogadro’s constant – which is 6.02e23, used in the above equation – simply press CNST<\/span>, then enter 28<\/strong>. You’ll see 6.02×10^23 across the screen. To get 6.24e18, the number of electrons in a Coulomb, you first need to realize that it’s the reciprocal of the elementary charge number, 1.60e-19. To get the elementary charge number, press CNST<\/span>, then 09<\/strong>. You’ll see 1.60×10^-19 across the screen.<\/p>\n The SHARP EL-520W has 52 built-in constants, many of which I’ve never had occasion to use. However, I’ll discuss more about them in future posts:)<\/p>\n