0
Mathematical Constants
Intriguing, ubiquitous, and at times mysterious, numerical constants set the allowable limits for all universal phenomena. Whether your questions involves π, Avogadro's number, Planck's constant, the atomic mass unit, or any of the other multitudes of immutable numbers used in science, this is the category where they should be asked.
2,332 Questions
What is the advantage of product differentiation?
A company that excels at product differentiation can normally demand a higher price for a product because of its perceived higher quality.
Here is how you calculate a coupling constant J: For the simple case of a doublet, the coupling constant is the difference between two peaks. The trick is that J is measured in Hz, not ppm.
The first thing to do is convert the peaks from ppm into Hz. Suppose we have one peak at 4.260 ppm and another at 4.247 ppm. To get Hz, just multiply these values by the field strength in mHz. If we used a 500 mHz NMR machine, our peaks are at 2130 Hz and 2123.5 respectively. The J value is just the difference. In this case it is 2130 - 2123.5 = 6.5 Hz This can get more difficult if a proton is split by more than one other proton, especially if the protons are not identical.
What symbol can't be repeated or subtracted?
V, L and D (5, 50 and 500 respectively). Repetition and subtraction are redundant because VV would be X, LL would be C, DD would be M, VX would be V, LC would be L and DM would be D. Although you could theoretically subtract V from L to get VL=45, the accepted convention does not permit any subtraction of 5, 50 or 500. 45 would be more correctly formed with XLV.
What is the relationship beween avogadros number and the mole?
Avogadro's number represents the number of units of a substance in one mole of the substance. These units may be electrons, atoms, ions, or molecules, depending on the substance.
How can the sum of 3 odd numbers is always odd?
When you add an odd number to an odd number, you get an even number. When you add an odd number to that even number, the sum is always odd. Don't believe it? Try a few examples yourself.
e isn't a number, its a mathematical constant.
It is sometimes called Euler's number after the mathematician Leonhard Euler.
What is quantum leap compared to change?
Change can happen over time,
a quantum leap does not.
The expression: a quantum leap comes from physics and refers to the orbit of electrons around the nucleus. The electrons cannot be anywhere but have to be in distinct energy regions. So for an electron to change orbit it must leap to the next energy or lower energy level it can not do it gradually.
Similarly if a quantum leap is made it is a radical change not a gradual change. New discoveries in science can revolutionise traditional thinking overnight. One could say a quantum leap in understanding was made. Whereas, just about everything can change slowly over time but that is not a quantum leap.
Change can be slow and gradual or even fast and high paced. The student quickly improved his language skills at the immersion school. Is an example of change.
A quantum leap is jumping from one understanding to another. The student finally understood the difference in verb endings for the past tense and a quantum leap was made in his ability to understand and speak intelligibly. Vast progress was made when an impediment (obstacle) was removed.
What is this number called 3 000 000 000 000 000 000 000 000 000?
"Three times ten to the twenty-seventh power."
