IB+MYP+MESUREMENTS

Measurements
*What is a physical quantity? >> It is a quantity that can be measured. A physical quantity consists of a **//numerical magnitude//** and a //**unit**//. A **quantity**: something that can be quantified (given a number to) A **physical quantity**: a physical property that can be expressed in numbers. example) 7m


 * Examples of physical quantities
 * The seven base quantities and their SI units**
 * || 7 Fundamental quantities || Definition || Unit ||
 * 1 || Distance || To define position of how far an object is away from us. || metre ||
 * 2 || Mass || To quantify how much matter the object consist of. || kilogram ||
 * 3 || Time || To distinguish between different events. || second ||
 * 4 || Current || To quantify the rate of flow of electrons || ampere ||
 * 5 || Temperature || To quantify how hot a substance is. || kelvin ||
 * 6 || Mole || The amount of substance of a system which contains many elementary entities(i.e. atoms) in 0.012kg of Carbon 12 || mol ||
 * 7 || Luminosity || To quantify luminous intensity of a light source || candela ||

[|Bill Nye Metric system] from youtube.com
 * Base quantity || Name of SI unit || Symbol for SI unit ||
 * Lenght || metre || m ||
 * Mass || kilogram || kg ||
 * Time || second || s ||
 * Elecric current || ampere || A ||
 * Thermo dynamic temperature || Kelvin || K ||
 * Luminous intensity || candela || cd ||
 * Amount of substance || mole || mol ||

*What are not examples of derived [|SI units]? >> Area, Volume and Speed are some common derived quantities and units.

*List prefixes >> Refer to the table on page 11 in your text. __//Some common SI prefixes//__ 

Example 1.1 Donovan Bailey of Canada broke the 100m sprint world record at the 1996 Atlanta Olympics, with a time of 9.84s. With this record, he became the 'world's fastest man'. In contrast, a dog runs at a speed of 30km h -1. If the dog chases Donovan Bailey, will the dog catch up with him? Average speed of DB = DISTANCE / TIME = 100m / 9.84s = 10.2 ms -1 Convert DB's speed to km h -1 ; 10.2 ms -1 = 36.7 km h -1 Since DB's speed is faster than the dog, he will outrun the dog __over a distance of 100m__. But his speed will drop and the dog may eventually catch up with him!

Caliper: an instrument for measuring the distance between two point

Vernier Calipers Applet __ Vernier Calipers __ Micrometer Calipers Applet __ Flash Micrometer __

__//Q1. Describe how you would find the thickness of a sheet of paper used in a foolscap by using a micrometer.//__ Check zero point. Close micrometer onto paper. Take reading of both scales.

__//Q2. Describe how you can make the above experiment a fair test.//__ >>Try the above procedure several times using several sheet of paper.

__//Q3. Describe how you would determine the period as accurately as possible. Then explain// why. __ Measure the time for 20 complete oscillations, divide the measured in time by 20. The reason why measure the time for 20 swings then calculates the time for one swing is to make the measurement more accurately.

__//Q4. What precaution should be taken when using a measuring cylinder?//__ Make sure that the measuring cylinder is vertical. Make sure that the eye is level with the liquid surface(meniscus), avoiding parallax error.


 * **The units of these seven base quantities are known as the __SI units.__ All other units are derived from the SI units.**

A PRECISE measurement is a reproducible measurement.
Precision vs Accuracy


 * Pendulum Experiment [ Text pg. 15 ]**


 * Length || Time for 20 oscillations || Period || T 2 ||
 * l/m || t/second || T/s || T 2 /s 2 ||
 * 0.600 ||  ||   ||   ||
 * 0.700 ||  ||   ||   ||
 * 0.800 ||  ||   ||   ||
 * 0.900 ||  ||   ||   ||
 * 1.000 ||  ||   ||   ||


 * Length || Time for 20 oscillations || Period || T 2 ||
 * l/m || t/second || T/s || T 2 /s 2 ||
 * 0.600 ||  ||   ||   ||
 * 0.700 ||  ||   ||   ||
 * 0.800 ||  ||   ||   ||
 * 0.900 ||  ||   ||   ||
 * 1.000 ||  ||   ||   ||


 * Good report example** [[file:Science Practical Report.docx]]

What does the word mean? <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">The Mole is a number. It is **6.02 X 10****23**. <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">One mole of any specified entity contains 6.02 x 1023 of that entity.
 * [|Mole]**
 * Word || number ||
 * a pair || 6 ||
 * a mole || 2 ||
 * a dozen || 12 ||
 * half a dozen || 6.02 X 1023 ||

How big is a mole? from youtube.com/TED-Ed/Daniel Dulek media type="youtube" key="TEl4jeETVmg" width="448" height="251" <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">When we measure one mole of a substance on a balance, this is called a "molar mass" and has the units g/mol (grams per mole).
 * <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">A molar mass is the mass in grams of one mole.
 * <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">One mole contains 6.022 x 1023 entities.

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">Scientists use the following equation. <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">**Moles** **(N) x molar mass (Mr) = mass** **(m)** <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">**( Unit for Moles is in** //mol//**, Molar mass is in** //g/mol// **and** **Mass is in** //grams// **)**

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">It is the amount of atoms if we take the atomic mass of an element and put it in grams.

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">There are **<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">6.02 x 10 **<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">**23** of carbon-12 atoms in 12g of carbon, which means:

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">There are **<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">1 mole **<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;"> of carbon-12 atoms in 12g of carbon.

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">Ex1) There are 1 mole of atoms in 1g of hydrogen. There is 1 mole of atoms in 4g of helium. 1 is the atomic mass of hydrogen and 4 is helium.

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">relative molecular mass
<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">(Chemistry) the sum of all the relative atomic masses of the atoms in a molecule; the ratio of the average mass per molecule of a specified isotopic composition of a substance to one-twelfth the mass of an atom of carbon-12. Symbol:**Mr (**Definition from thefreedictionary.com)

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">Ex2) We can also do this for molecules. Water is H20. Water has 2 hydrogen and 1 oxygen. The atomic mass of oxygen is 16. <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">>> H 2 <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">0 = 1 x 2 +16 x1 = 18, This means 18g of water contains 1 mole of water molecules.

2. Atomic mass 3. Mass of one mole of OZONE || 2. Atomic mass 3. Mass of one mole of HCl || 2. Atomic mass 3. Mass of one mole of Calcium carbonate || 2. Atomic mass 3. Mass of one mole of NH 4 || 2. Atomic mass 3. Mass of one mole of Sodium hydroxide || More practice from [|misterguch.brinkster.net] and [|Chemteam.info]
 * Calculate the mass of one mole of each chemical compound. You can use the periodic table of elements. Show your working!
 * a. OZONE || 1. Chemical formula
 * b. Hydrochloric acid || 1. Chemical formula
 * c. Calcium carbonate || 1. Chemical formula
 * d. Ammonia || 1. Chemical formula
 * e. Sodium hydroxide || 1. Chemical formula

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">Practice questions <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">1. Calculate the mass of 0.25 moles of carbon dioxide <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">2. Calculate the moles in 124.5 g of oxygen gas <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">3. Calculate the molecular mass of a pure substance if 1.75 moles of the substance has a mass of 29.792g. <span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">

<span style="background-color: #ffffff; font-family: 'Lucida Sans','Lucida Grande','Lucida Sans Unicode',Verdana,sans-serif;">Notes from chemistrylecturenotes.com Mass Mole calculations from [|ausetute.com.au] Make a mind-map using Brainpop and submit it as an exit ticket.

Challenge questions! Mole Ratio from Chemical Formulae from youtube.com/GetChemistryHelp media type="youtube" key="hQ6_BxJwvB0" width="448" height="251"