- Scientific Notation- a way of expressing numbers that are extremely big or extremely small by putting one number before the decimal point, then multiplying by a power of 10.
- ex. Avogadro’s Number 6.022140857 × 1023
- Measurement in Chemistry- the metric system is always used.
- Metric Prefix Mneumonic:
- King Henry Died by Drinking Chocolate Milk. (Kilo,Hecto,Deka, BASE, Deci, Centi, Milli)
- Units of Measurement
- Grams for mass/weight
- Volume- Liters
- Length/Distance- Meters
- Temperature usually in Celsius
- To convert from Fahrenheit to Celsius use formula 5F= 9C +160
- To convert from Celsius to Fahrenheit use formula 9C= 5F-160
- Metric Prefix Mneumonic:
Hello and welcome to our lesson on scientific notation and measurement.
Scientific notation is designed to be a more convenient way to express either really big or really small number values.
And there is a really easy trick to writing a value in scientific notation… you just put the first number of your value before a decimal point and then you write the rest (sometimes rounded) and multiply the place values by a power of ten.
So for example here is Avogadro’s number (an actual value I don’t even know how to correctly express.) However I do know that 6.02 times 10 to the 23rd power is Avogadro’s number.
So here is a real world example. If you are familiar at all with Star Trek you might know that one of the things they can do in the future is teleportation. Scientists have attempted to quantify the amount of data or bits it would take to just send the information contained in the human brain to be about 2.6 tredicillion bits of info. An easy way to express that value with scientific notation is 2.6 times 10 to the 42nd power. Additionally to transmit that much information with current internet speeds it would take 4.85 quadrillion years or 4.85 times 10 to the 15th power years. See how scientific notation can make handling large or really small values easier! That length of time btw is about 3.5 times 10 to the 5th times longer than the age of the universe.
Our other focus in this lesson is a review of the metric prefixes. So a base metric unit is dependent on what is being measured. The prefixes abbreviated above are all based on a factor of 10. KHDBDCM. That’s kilo, hecto, deca, base, deci, so you can have a value of your base unit and then convert that value into a smaller value or larger. If you want to convert from a smaller units value to a larger nits you would move the decimal to the left…this will reduce the numerical value because the units will be larger. Thus if you want to convert from a larger unit to a smaller one, you would move the decimal to the right. This increases the numerical value because the units are now smaller.
So for your metric base units, If it is a solid or you are measuring mass it is likely to be in grams, if you are measuring a liquid or a volume the unit is in liters and if you are measuring distance/length typically meters.
Another important measurement conversion is that for temperature. This formula is easy to use as you can just plug in the value you know (either C for Celsius or F for Fahrenheit) and solve for the variable you want. A simple mnemonic that i learned that might help is to remember that you have five fingers (5F) and cats have 9 lives (9C). So of you can remember those values are connected and recall either version of this formula you will get to the right temperature. So let’s check the formula real quick with a conversion we all know 32 degrees F is the same as 0 Celsius. If we convert 0 degrees C to F we plug in 0 for C which leaves us with 5F equals 160 and 160 divided by 5 equals 32!
So in review, we use scientific notation to simplify the way we refer to really big or really small numbers. The metric system is a measuring system based on factors of 10 and the mnemonic to remember the order from big to small is King-Kilo, Henry-Hecto, Died-Deka, By-Base Unit, Drinking-Deci, Chocolate-Centi Milk- milli. The base units that are used by the metric system are grams for measuring mass, liters for volume, and meters for length. And lastly to convert from Fahrenheit to Celsius or vice versa just remember to use the equation 9C= 5F-160.
Thank you for reviewing scientific notation and measurement. Now go out and be your best self today and Happy Nursing!