Conceptual Chemistry

1. Use examples to explain the various branches of science. 2. Distinguish between qualitative and quantitative observations. 3. List the SI units of measurement and common prefixes. 4. Convert units using dimensional analysis. 5. Diagram and explain the various components of experimental design. 6. Calculate the density of an object from experimental data.

1.) Use examples to explain the various branches of science. 2.) Distinguish between qualitative and quantitative observations.

1.) Analytical 2.) Classification 3.) Invention 4.) Scientific Method

 Involves laboratory analysis to find out what something is made of. Example: forensics 1. Quantitative – numerical amounts measured Example: 1.9 cm, 2.00 g, 55.3 o C 2. Qualitative – measured with senses Example: short, heavy, hot

 Gives us a common language. Example: Chemistry- elements on the periodic table Biology- plants vs. animals

 Creating or producing by using your imagination.  There are no rules! Example: mobius strips

 Method of research in which a problem is identified, data is gathered, a hypothesis is formed from this data, and the hypothesis is tested.  Used to prove or disprove something.  There are strict rules!

1. Biological 2. Physical 3. Earth

 The study of living things. (bio = life)  Video Example 1 Video Example 1  Video Example 2 Video Example 2

 The study of non-living materials and or energy.  Video Example 1 Video Example 1  Video Example 2 Video Example 2

 The study of non-living earth features.  Video Example 1 Video Example 1  Video Example 2 Video Example 2

 Link 1 Link 1  Link 2 Link 2

Diagram and explain the various components of experimental design.

 Used for formal research.  Observation/Stating a Question or Problem  Gathering Information  Forming a Hypothesis  Experimental Design  Recording and Analyzing data  State a Conclusion  Repeat

 Varies depending on the project.  Looking to prove or disprove a point.

 Research what is already known.  Use and keep track of credible sources.

 If…then…because…

 Change only 1 variable.  Controls: Normal, unchanged part  Experimental Group: Changed part ▪ Independent Variable: “I” change the “I”ndependent variable. ▪ Dependent Variable: Outcome you hope depends on your change.

 Data Tables  Graphs  Calculations

 Based on experimental results.  Use gathered information to support original question or problem.

 Multiple trials lead to more reliable results.

1.) Draw a picture of the control group and experimental group. 2.) Label the independent variable. 3.) Describe the dependent. Control GroupExperimental Group

 List the SI units of measurement and common prefixes.

Metric Ruler

 Measure and diagram the sheet of paper in your Lab Notebook.

Graduated Cylinder

 Science uses the metric system.  Basic Units  Also called Standard International or S.I. Units

QuantityUnits Symbol Example Lengthmetersmaverage human ~ 1.6 m Masskilogramskg1 penny ~ 1 g VolumeLitersL2 L bottle Densitymass/volumeg/mL or g/cm 3 density of water ~ 1 g/mL Temperature kelvinKroom temperature = 293 K Timesecondss1 min = 60 sec PressurePascalsPa101,000 Pa = sea level

 Basic Unit is kelvin.  It is found by o C = kelvin

o C = kelvin  0 o C is actually 273 Kelvin. Still lots of energy. o 0 o C = 273 K  100 o C is equal to 373 K o 100 o C = 373 K  -273 o C is equal to 0 K o -273 o C = 0K o This is called absolute zero. Everything stops at this temperature.

1. Antarctica can get as cold as -100 o C. How many K is this? 2. If global warming continues, Earth could earn an average temperature of 313 K. How many o C would this be?

Nano-nbillionth1/1,000,000,000DNA PrefixSymbo l MeaningMultiplied sizeExample tera-Ttrillion1,000,000,000,000terabytes giga-Gbillion1,000,000,000gigabytes mega-Mmillion1,000,000mega million kilo-kthousand1,00010 kilometer race = 7.2 mi centi-chundredth1/100finger nail milli-mthousandth1/1,000thickness of penny micro-µmillionth1/1,000,000human cells

 Calculate the density of an object from experimental data.

 Density: The ratio of the mass of an object to its volume.  Density = mass / volume  The density of substances changes with temperature.

 Show with pictures, label all values, and show math 1) Measure dimensions of Block (cm) 2) Measure mass of Block (g) 3) Calculate Density of Block

 Show with pictures, label all values, and show math 1) Mass of empty Graduated Cylinder 2) Measure 50 mL of Water in Cylinder 3) Mass of water and Cylinder together 4) Calculate Mass of Water 5) Calculate Density of Water

 Show with pictures, label all values, and show math 1) Measure mass of object 2) Use partially full G. Cylinder – record volume 3) Place object in G. Cylinder – record new volume 4) Calculate Volume of object 5) Calculate Density of object

 What is the density of an object with a mass of 4.00 g and a volume of 4.00 ml?

 Density is the ratio of the mass of an object to its volume  Ie: Water density = 1.0 g/ml Cork density is less than 1.0 g/ml  The formula for density is D= mass / volume

 If you have two objects of the same size, and object A is more dense than object B, which one will have more mass?

 Dice

 Wax

 Corn Syrup

 Convert units using dimensional analysis.

 You must always SHOW WORK when converting units. This will pay huge dividends for your entire science future.

 Any number can be written over one. It will not change the value. o 7/1 = 7  Any number divided by itself equals one. o 7/7 = 1  If you multiply by one, it will stay the same.  So if you multiply by a conversion factor, you are really multiplying by one.  Any amount divided by the exact same amount equals one.  *This is called a conversion factor (a fraction with equal amounts on top and bottom, but in different Units)

1. Write down the given number, with units. 2. Choose a conversion factor that will get you away from what you’re GIVEN, and get you to what you WANT. Remember, the TOP and BOTTOM of the fraction must be an EQUAL amount, so it really only equals ONE. 3. Place your conversion factor next to the given number so that it is MULTIPLIED using A FRACTION. Make sure what you WANT is on top, and what your getting rid of is on BOTTOM. 4. If multiple changes are needed, just multiply by multiple conversion factors. 5. Cross of units that appear on TOP and BOTTOM. The only unit left should be the one you WANT. 6. In your calculator, multiply all TOP numbers, divide by any BOTTOM numbers.

 One step problem: Convert 3 weeks to days.  Convert 62 inches to centimeters (1 inch = 2.54 cm)  Convert 75 miles to kilometers (0.62 miles = 1 km)

 Two step problem: Convert 3 weeks to hours.  Four step problem: Convert 3 weeks to seconds.

Example 2: Convert 215 miles into Kilometers.

1. How many fingers would be on 12 hands? 2. How many centimeters would be in 200 meters? 3. How many kilometers is 2,043 meters?