Rachael

 Homework: 20/01/11 __**//Poem Assessment//**__ Chapter 3 Summary Questions. Sorry about the unanswered ones... they didn't make sense :-/  __**//Science Homework: Chapter 3 Questions - Bonding//**__

1. There are two electrons in a single bond and four electrons in a double bond. 2. The electrons in a noble gas are special because they are stable, they have the maximum amount of electrons in their outer shell (except for helium which has 2) and they are non reactive and cannot form compounds. 3. - 4. The main difference between covalent and ionic bonding is in an ionic bond, the atoms are bound together by the attraction between oppositely-charged ions, while in a covalent bond the atoms are bound by shared electrons. 5. An anion is a negative ion and a cation is a positive ion. 6. - 7. Metals conduct electricity because they contain mobile electrons, which are called a ‘sea of electrons’, which allow the metal to conduct electricity. 8. Magnesium has a high melting point than sodium because magnesium has 2 delocalized electrons for every one magnesium atom, therefore it forms smaller ions than sodium, which pack more closely together. The higher number of delocalized electrons in magnesium also pull the positively charged even closer together, hence giving it a higher melting point. 9. Intermolecular forces are attraction between separate molecules, these strength tends to vary from substance to substance. One example would be H 2 O.

 __**Bubble Lab Research**__

__**Research Question:**__ How does the addition of glycerin or corn syrup affect the physical properties of bubbles? __**Research:**__ Bubbles seem to form perfect spherical shapes, because the mixture is like a balloon. The mixture, when some is taken and inflated, surrounds the air inside the bubble because the liquid skin is stretchy. Glycerin can make bubbles last longer because it is hygroscopic and this helps to prevent the evaporation of water. Its high viscosity increases the time it takes for materials to flow downward in the bubble. Corn syrup on the other hand can makes bubbles last longer because of the same thing.

 __**Materials:**__

 • 2 beakers 300 mL or greater  • 100 mL and 50mL Graduated cylinder  • Water  • Liquid dishwashing soap <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin-bottom: 5.2px; margin-left: 36px; margin-right: 0px; margin-top: 0px; text-indent: -36px;"> • Glycerin, small bottle <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin-bottom: 5.2px; margin-left: 36px; margin-right: 0px; margin-top: 0px; text-indent: -36px;"> • 2 Pipe cleaners <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin-bottom: 5.2px; margin-left: 36px; margin-right: 0px; margin-top: 0px; text-indent: -36px;"> • Stopwatch <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin-bottom: 5px; margin-left: 36px; margin-right: 0px; margin-top: 0px; text-indent: -36px;"> • Ruler

<span style="font: normal normal normal 14px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">__**Method:**__ <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">1. First mix your bubble solutions using a beaker for each, using the measurements in the table below. Label each formula with a permanent marker and tape.

<span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">2. Next, make a pipe cleaner wand for each solution. You can wrap the tops of the bottle for this process but make sure the circles are closed and the wand diameters are the same. <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">3. Test your bubble solution outside and blow a bubble and catch it on your wand and immediately start timing how long the bubble lasts. Practice this a few times before you start recording so you get the hang of it. <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">4. Complete 15 tests of each solution. <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">5. Record your data in a data table and also make sure to note relevant observations such as bubble sizes.

<span style="font: normal normal normal 14px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">__**Data tables:**__ <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">Solution #1: Detergent Only <span style="font: normal normal normal 12px/normal 'Comic Sans MS'; letter-spacing: 0px; margin: 0px;">Solution #2: Detergent & Glycerin

<span style="display: block; font: normal normal normal 14px/normal Helvetica; margin: 0px; text-align: center;"> <span style="display: block; font: normal normal normal 14px/normal Helvetica; margin: 0px; text-align: center;"> __**//Science Homework: Chapter 5 Questions//**__

1. a) Fizzy Drink  b) Salt Water

2. An alloy is special because it combines two or more metallic elements especially to give greater strength or resistance to corrosion.

3. A suspension contains the largest particles.

4. I would use my shirt and stretch it tight over an empty coconut. I would then let the sand and water mixture filter through the shirt hopefully keeping the sand out. I don’t think the water would be 100% pure but it would be much purer than if I hadn’t filtered it at all.

5. Water boils at 100°C but ink boils at a much higher temperature.

6. To separate a mixture of alcohol and water you could heat the mixture because alcohol evaporates at a lower temperature than water. Therefore the condensation that forms when you heat the mixture is alcohol and what is left should be water.

7. You can test ethanol and water to find out which is which by attempting to light the mixture on fire with a splint. If it catches on fire it means it is ethanol because ethanol is flammable and if it does not then it’s water because water is not flammable.

<span style="display: block; font: normal normal normal 14px/normal Helvetica; margin: 0px; text-align: center;"> __**//Chapter 5 Summary Questions//**__

1. Melting is not a method of separation.

2. Fractional distillation separates liquids which have different boiling points.

3. The statements which are true are |, || and |V.

4. The colour of raw sugar is removed by adding charcoal.

5. a) Y (water) is more dense because the particles are closer together and this is because they "want" to hydrogen bond with each other, which is energetically favorable.  b) Vinegar and oil can also be separated by this method. c) When the third liquid is added and then the mixture is shaken the three liquids will mix together. This is called emulsion. d) You can also separate liquid mixtures by simple distillation.

6. a) Get a piece of filter paper, draw a circle in a separated colour and put a coloured spot in the center and allow it to dry. Place it over an evaporating basin to support the filter paper. Add drops of water to the centre of the coloured spot, very slowly, one by one. Watch the colours separate into bands.  b) - c) If the ink was insoluble in water and soluble in alcohol I would substitute the water for alcohol to drip on the ink.

7. a) The first separation carried out in the manufacture of sugar is when the juice is boiled which causes evaporation to remove some of the water in the juice, next the raw brown sugar and molasses are separated in a spinning centrifuge which is like a spin drier. The last separation in the manufacture of sugar is when the pure sugar crystals are separated and dried.  b) Two other products made from sugar cane are molasses and rum. c) You could remove the colour from sugar cane in the laboratory by using charcoal.

8. a) Three different types of filtration at home or school are the water coolers at school, a sift which is sometimes used in baking and the air conditioner.  b) Using a teabag is a system of filtration because the tea leaves in the teabag can’t come out so the colour and flavor are filtered out of the bag. c) Two products distilled from crude oil are petrol, which is used in cars etc, and diesel which is also used in cars.

9.

b) i) 940 ii) 1400 c) I would conduct an experiment for the solubility of a solid which is defined by 'the mass of solute which will saturate 100g of water at that temperature' and change the temperature each time to obtain different results. Maybe by heating the mixture every so often. d) The differences I notice when comparing the figures for sodium chloride to those in my graph that the solubility of sodium chloride increases a lot slower as opposed to those of sodium nitrate.

10. b) What is unusual about the curve is the fact that from 40<span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">°C to 80°C the solubility decreases slightly.  c) If you saw a saturated solution of sodium sulphate warmed from 40<span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">°C to 80°C you would see the solubility decrease as shown in the graph.

The Scientific Method
=== The scientific method is a series of steps that you can use in everyday life to help analyze and solve problems. Some say it is made of four steps and others say five. When we are unsure of something we apply the scientific method to find the answer. Also, when we wonder why something happens we once again apply it. The scientific method was more recognized than invented but many authors say it dates back to ancient === ===<span style="color: #ff009b; display: block; font: normal normal normal 13px/normal Times; letter-spacing: 0px; margin: 0px;">artisans *Capital (: * <span style="display: block; font: normal normal normal 13px/normal Times; letter-spacing: 0px; margin: 0px;">, Greeks, Arabs, Spaniards, and many others. Today we still use the scientific method even without being aware of it. === ===<span style="display: block; font: normal normal normal 13px/normal Times; letter-spacing: 0px; margin: 0px;">I understand the scientific method better as five steps as it seems clearer to me but others may use four. The five steps are first, identify a problem, which means finding out what you want to analyze or solve. Then you research the problem by looking up maybe the history of what your problem is or how often the problem occurs etc. Next, formulate your hypothesis, this means look at your problem and your research and formulate a statement of how you think the problem works. This would normally include the words “if” and “then.” Once you have written your hypothesis you can conduct an experiment. Your experiment should be relevant to your problem but you should run the experiment multiple times and should help to eventually answer your hypothesis. Finally, you can reach a conclusion. Once you have conducted your experiment and recorded your data, you can reach a conclusion that should finally answer your hypothesis. Excellent Explanation. === ===<span style="display: block; font: normal normal normal 13px/normal Times; letter-spacing: 0px; margin: 0px;">Scientists use the scientific method when they look at the world around them and wonder how something happens or why something happens. They want to know the answer to a question and use the scientific method to solve it. Some scientists even use the scientific method to elaborate on current knowledge. === ===<span style="display: block; font: normal normal normal 13px/normal Times; letter-spacing: 0px; margin: 0px;">We use the scientific method outside of the classroom for so many different things. For example, if I’m cooking something and I think, ‘if I put in more water then it will be too watery.’ I put in the water and then taste the food and it turns out to be fine therefore my conclusion is the extra water did not make the food too watery. I’ve just used the scientific method to answer that simple problem. There are many times when we use the scientific method but we are not aware of it because all the questions and answers go through our heads quickly without names to the different steps, but we’re still using the scientific method. ===

Good Example.

Sources: <span style="color: #000099; display: block; font: normal normal normal 12px/normal Times; letter-spacing: 0px; margin: 0px;">__[|**http://www.factmonster.com/cig/science-fair-projects/understanding-using-scientific-method.html**]__ <span style="color: #000099; display: block; font: normal normal normal 12px/normal Times; letter-spacing: 0px; margin: 0px;">__[|**http://www.scientificmethod.com/sm5_smhistory.html**]__ <span style="color: #000099; display: block; font: normal normal normal 12px/normal Times; letter-spacing: 0px; margin: 0px;">__**[]**__

Didn't find any problems, and I liked the text because it was easy to understand =D / Oscar <span style="color: #000099; display: block; font: normal normal normal 12px/normal Times; letter-spacing: 0px; margin: 0px;"><span style="color: #fdff00; font-family: 'Comic Sans MS',cursive; letter-spacing: 0px;">﻿ __<span style="color: #000000; font: 12px Times; fontstyle: normal; fontvariant: normal; fontweight: normal; letterspacing: 0px; lineheight: normal; margin: 0px; marginbottom: 0px; marginleft: 0px; marginright: 0px; margintop: 0px;">i liked how you mentioned to test your hypothesis multiple times. good overall olivia __ Well Done Miss (: - great work definitely showed your understanding of the scientific method!- Keep it up :D ! - Ella Other then the mistake ella pointed out i have not found any mistakes.. Well Done ! - I liked how it was easy to understand and how it was dragging anything out. - Taylor.   ﻿Once again ! it was Great, and very easy to understand :D ! Well donee girl ! :) - Marce x   I didnt find any other mistakes that were not already shown, i like how it was very detailed but didnt make it complicated, and easy to understand, Good job - Millie

__**<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Scientific Investigation **__

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Question: Can a potato generate electricity?

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">I will use the scientific method by following each of the steps to hopefully come up with my conclusion.

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">I could attach a potato to a light to see if it causes it to light up. If I want to intensify the light, I could see if adding more potatoes causes the light to do so.

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Hypothesis: If I connect potatoes to a light bulb, as I add more potatoes, the light from the bulb will get brighter.

<span style="font-family: 'Comic Sans MS',cursive;">Observations: One day I heard my parents complaining about the electricity bill and how high it was. I thought well there must be something I can do to at least maybe minimize it by a little. Then a thought occurred to me, I read a lot at night and I'm sure the bulb in my lamp burns a lot of electricity. I decided to try and find something alternative to use instead and I'd heard before about potato clock, so why not a potato light.

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Independent Variable: number of potatoes

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Dependent Variable: intensity of the light

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Variables to control: the size of the potatoes

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Experimental group: addition of more potatoes

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Control group: the initial number of potatoes

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Materials:
 * <span style="color: #000000; font-family: 'Comic Sans MS',cursive;">3 fresh potatoes (relatively the same size),
 * <span style="color: #000000; font-family: 'Comic Sans MS',cursive;">A few copper electrodes (depends on how many potatoes you have)
 * <span style="color: #000000; font-family: 'Comic Sans MS',cursive;">A few zinc electrodes (this also depends on the number of potatoes you have. You can use the removed shell of a broken AA battery for the Zinc electrode.)
 * <span style="color: #000000; font-family: 'Comic Sans MS',cursive;">A light bulb
 * <span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Alligator clips/ Leads.

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Method:
 * 1) <span style="font-family: 'Comic Sans MS',cursive;">First, insert a copper electrode and a zinc electrode into a potato, they can be close but make sure they’re not touching each other.
 * 2) <span style="font-family: 'Comic Sans MS',cursive;">Then take the alligator clips/leads and connect them from the electrodes to the lightbulb.
 * 3) <span style="font-family: 'Comic Sans MS',cursive;">Make observations and record data.
 * 4) <span style="font-family: 'Comic Sans MS',cursive;">Next, you can add more potatoes to create an even bigger circuit.
 * 5) <span style="font-family: 'Comic Sans MS',cursive;">Once again, make observations and record data.

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">Data table:


 * NUMBER OF POTATOES || LIGHT BULB INTENSITY || OBSERVATIONS ||
 * 1 ||  ||   ||
 * 2 ||  ||   ||
 * 3 ||  ||   ||
 * 4 ||  ||   ||

<span style="color: #000000; font-family: 'Comic Sans MS',cursive;">http://www.freesciencefairproject.com/projects/electricity_from_potato.html <span style="color: #000000; font-family: 'Comic Sans MS',cursive;">http://www.suite101.com/content/generating-electricity-with-potato-batteries-a99472

__**Task 3**__

QUESTION: do different coloured liquids have different PH scales?

HYPOTHESIS: if I add colour to water then the PH scale should change.

IV: the colour

DV: ph scale

CONTROL GROUP: the glass of water

EXPERIMENTAL GROUP: the glass of water with colour.


 * VARIABLES TO CONTROL: the amount of water and the amount of colour. **