4th Quarter Update

Welcome back from break!

Here is an update on the happenings in the science room this quarter:

Physical Science students will be looking at the chemical formulas in common household items and figuring out where it is an ionic or covalent bond.

Advanced Biology students are finishing up their independent body system projects.

Earth Science is creating a webpage to explain how different areas are meeting the challenges of a changing environment. Stay tuned- we will post it April 23 and it should be really exciting!

Kitchen Biology is making yogurt tomorrow. Yum!

Biology is starting a unit on invertebrates. Yesterday they went outside and observed the different invertebrates in the school yard and came up with some excellent questions.

Chemistry is designing torpedoes using baking soda and vinegar as the propellant.

Concurrent enrollment students go to Idaho Academy of Science

I've got some pretty amazing students. I generally let them speak for themselves on this blog, but I couldn't resist bragging a little bit about my concurrent enrollment college students. They are an amazing bunch of students.

This Friday marks the first day of spring break. It also marks the 57th Annual Idaho Academy of Science and Engineering Symposium. Four of my students are choosing to spend the first day of their spring break at this conference, attending talks from scientists around the state, and chatting to college students about the undergraduate research happening at the universities around Idaho. It is a great way to see all the exciting research happening here in Idaho, and to get an idea of what they might want to tackle when they get to college.

I don't always say it, but I am so proud of my students.

Covalent Bonding by Madalyn

       Covalent Bonding: “A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding.”

In Covalent Bonding only non metals and nonmetals can bond together. The term Covalent Bond dates from 1939. The 2 elements combining do not have to be the same element they can be any two nonmetals. Covalent bonds are important because if nonmetals couldn't bond we wouldn't have a lot of the things we can't live without like water (H2O). What are the most common elements that bond using covalent bonding? Covalent bonding is the most common type of element bonding. It is also the most important type. 

Solubility and Molarity by KZ

Solubility is a chemical property that relates to the ability for a given substance, the solute, to dissolve in a solvent. The measure solubility is measured in terms of how much solute can be dissolved in a solvent. The solution that is left over is called a saturated solution. Molarity is a concentration unit, defined by the number of moles of solute divided by the number of liters of a solution. The reason why molar solubility is important is because we can measure the amount of solute that is dissolved in a specific substance, called the solvent.

Key Facts:

·         The molar solubility of a compound can be calculated directly from its solubility product.

·         Even if the solubility products of two compounds are similar, their molar solubility can be largely different.

·         A solute may refer to the dissolved substance in a solution.

·         The solubility of a substance depends on the mass of a solute, volume of a solvent, and temperature.

·         As temperature goes up, the solubility of the solid goes up.

·         A mixture with the same composition throughout is a homogeneous solution.

·         A solution in which water is the solvent is called an aqueous solution.

·         When two liquids are completely soluble in each other they are miscible.

·         Most gases become less soluble in water as the temperature increases.

·         Molarity= mol/L

Examples:

·         In a salt water solution, what would the salt be considered? Answer: Solute

·         When you stir cocoa powder into milk, what is the milk considered? Answer: Solvent

·         What is the molarity of a solution containing 0.32 moles of NaCl in 3.4 liters of solution? M= .032molNaCl/3.4solution= 0.094MNaCl

Questions:

·         What is the difference between molarity and solubility?

·         In the figure below, what solution is saturated?

Experiment Report by Shyenne

So this past week our class, kitchen chemistry, was doing independent experiments. Most of the people did experiments on yeast. Others were different and did fungus, fruits, or cocoa beans. Since yeast was the big topic, I am going to cover that. Some people tried to figure out a way to make bread sweeter by adding fruits, and sugar to the bread batter. Some were working on trying to figure out where the best spot is to place a sourdough starter, and it was the kitchen. When a student said that she placed a starter near the chemicals in the science room, and she stated that it went bad after the first day, was really cool. I did not think that it would change that fast but it did. Then I thought another good spot to place a sourdough starter would be in a place that was really humid like a greenhouse, or pump house, but it is not it went bad. Why do you think it went bad in the pump house?

So then we have the fungus, which did you know that fungus dies if left out in the open in the cold? That was pretty cool to learn. Then the fruit was cool because the apple, pear, strawberry, and an orange have all high acid levels. Lastly the cocoa bean, which melts quicker in hot water but it was no surprise that it did, and cocoa grows on a tree!

Lewis Dot Structures by Maicel

A Lewis Dot Structure is a diagram that shows the bonding between atoms within a molecule and the lone pairs that may exist in the molecule. They simply show the configuration of a molecule in a 2-D plane. To understand Lewis Structures you first have to understand the Lewis Theory.

            The Lewis Theory is based on Valence Electrons-the electrons in the outermost shell, Ionic Bonds-bond formed between nonmetals and metals, and Covalent Bonds-bonds formed between metals and metals. There is also something called the Octet Rule which states that in chemical bonding electrons are transferred/shared so that each atom may reach a more stable configuration i.e. the noble gas configuration which contains eight valence electrons.

            A Lewis Symbol for an element is composed of a chemical symbol surrounded by dots. These dots represent the valence electrons. The image below shows both Carbon with 4 valence electrons and Oxygen with 6 valence electrons. 

When drawing Lewis Structures it can get complicated, but there is an easy 7 step way to follow.

1.     Step 1: Find the Total Number of Valence Electrons

a.     Add the total number of valence electrons in the molecule. for example H2CO would have 12

b.    H-1, H-1, C-4, O-6=12

2.     Step 2: Find the Number of Electrons Needed to Make the Atoms “Happy”

a.     This means to makes the outer shell of the atom full

b.    H-1, H-1, C-4, O-2=8

                                      i.        Hydrogen is odd in the sense that it on wants one to complete its outer shell.

c.     In our example of H2CO, for each Hydrogen atom there will need to be a Carbon so that takes care each valence electron for the two Hydrogen atoms and then two of the four valence electrons for the Carbon atom.

d.    Oxygen will then bond with Carbon, but in this case you have to remember that Carbon sometimes creates a doubles bond with Oxygen. In this case it will create a double bond because carbon still needs 8 valence to complete the Octet Rule.

3.     Step 3: Determine the Number of Bonds in the Molecule

a.     Step 2 tells how many electrons are needed and Step 1 is how many electrons you have. Subtracting the number in Step 2 from the number in Step 1 gives you the number of electrons needed to complete the octets.

4.     The Lewis Structure Should then look like the image below

Lewis Structures take practice and some getting used to, but once you get the hang of them and understand that every element really just wants to be like the noble gases (except hydrogen, he’s the odd child) with eight valence electrons it makes things a little easier.

            Lewis structures are used to further understand the configuration of an element such as Carbon’s configuration is 1s^2 2s^2 2p^2 and looks like the image below. They are also used to get a better understanding for 3-D structures because in Lewis Structures lone pairs are demonstrated which could alter the 3-D shape or angle of a molecule.

Do you think you could draw the Lewis Dot Structure for H2O?

Ancient Idaho and two student created websites

In earth science we have been learning about Paleontology, and as part of that, student created a "museum exhibit" for a certain time period in Idaho's history. All of the projects were really neat, but I can share two with you, as the students decided to create a website as their project. How exciting, that they are creating websites!

Chauncey's:
http://triassicidaho.weebly.com/

Spencer's
http://paleogeneidaho.weebly.com/

Experiments by Bryce

There were three experiments done demonstrated by presentations that intrigued me. The first was the effect of an environment on sourdough starters. This experiment was done by placing sourdough starters in a hot humid room, a fridge, and a kitchen counter. The experiment tested for the smell, texture, bubble count, and consistency. The results were as they expected to be. The hot humid room starter became nasty in aroma and had a thick consistency, with little amount of bubbles. The fridge had minimal growth with more of a thin consistency, not much of a smell difference, and small bubble count. The kitchen counter had much growth, with a smooth fairly easy consistency, and a rich sour smell like a sourdough starter should.

The second experiment done that was interesting was the effect of sourdough starters due to usage of liquid. The experiment was done by placing soda, milk, and orange juice in sourdough starters and seeing how they were affected. There was little effect on each of them because there was limited time due to complications on original experiment. In the small result changes present the soda started to kill the starter, the orange juice was making it the starter grow fairly well, and the milk made the starter barely have any growth.

The third and final experiment was the amount of mold that grows on bread when placed in different environments. The actual experiment didn’t work out because there was no mold that grew after two weeks of the bread being in a plastic bag in the sun and in the shade. This intrigued me because the experiment was done with store bought bread and I know there is preservatives in this bread. It makes me wonder how healthy these preservatives are for humans and also how long it would take the store bought bread to mold.

3 Facts About Topic:

1.    All of these experiments were done with full of intentions of working and only one of them showed results.

2.    Even without results from two of the experiments the presentations were well put together and still very informative.

3.    All of these presentations were helpful on becoming informed about bread and how different effects will change the bread or starter of bread.

Question for Public:

What would be the best way and place to make bread? Once the bread is made where would be the best place to store it?

Why Topic is Important:

This topic is important because it helps expand the knowledge of bread and how to properly take care of it and the starters to making sourdough bread. These experiments were able to show the place best applicable for sourdough starters and placement of bread.

Gases by Jimmy

Gas variables

Gas is arguably the most interesting state of matter. It changes both its shape and size according to what is around it. Gasses are also very difficult to measure effectively, because many of the gasses are lighter than normal air. There are a few things that make gases react in certain ways. Volume, heat, pressure, and the amount of particles are the things most commonly looked at in gasses. They are also very closely related.

The first variable is volume. Volume is the geometric area of the container of the gas.  The volume of gas is measured by the container it is in, because it is very difficult to isolate gas. Volume is measured in liters (L). The volume of a gas can either be fixed or variable, depending on its container. A rigid container, like glass or plastic, will have a fixed volume. The volume inside of the container will stay the same no matter what happens. A flexible container, like a balloon, will have a variable volume. The volume will change depending on the other variables. A balloon will expand when you blow into it and add more particles.

The next variable is heat. Heat is how much energy is in the particles. The unit for heat is Celsius (C). The temperature of the gas will affect both the volume and pressure of it. The amount of heat is directly proportional to the kinetic energy of the particles of the gas; as the heat increases, the particles will move faster and faster.

The variable that changes the most depending on the others is pressure. The pressure of a gas changes based upon the volume, heat or the amount of particles present. There are three main units for pressure: atmospheres (atm), millimeters of mercury (mmHg), and Pascal (Pa). Each unit has their own purpose and is used in different scenarios. At sea level, standard atmospheric pressure is 1 atm, 760 mmHg, and 101.325kPa.

The last variable is the amount of gas. This is usually expressed in moles. A mole is 6.022 * 10²³ particles. This is the only variable that is changed by only adding or subtracting more particles. Often the amount of particles in a substance will be notated as “n”.

The way these variables interact is predictable. For fixed volumes, as heat increases or decreases, the pressure will do the same and vice versa. If the amount of particles is increased, the pressure will increase. In a flexible container, more than one variable will change most likely. If you increase the amount of particles, the pressure inside will increase and the volume will expand.

Gas variables are used to help many things in today’s life. The most common and simplest is blowing up a balloon. As the amount of particles in the balloon increases, the elastic container expands increasing in volume. Because the container is elastic, it will push back on the air inside of the balloon, increasing pressure. These are also used in things such as tires, hair spray, and airplanes. Some of the properties of gasses will also apply to the other states of matter. How can we use the relationship of the properties of gas to help out many other things in our society?

Sourdough starters by Emily

            How we covered the topic about sourdough starters is we did an experiment. Our experiment was to just make sourdough starters for only a period of 4 days. We didn't all stay in the same spot though, just to see if we could get different results. Two of us went outside, two of us went in the all, and then the rest stayed in the classroom. We also spread them out around the classroom when we had to let them set overnight. There was some in the window seal, some up on a high shelf, some in the back, and one on the mini fridge in the back. Most of them were going good for the first two days, then all of a sudden they necessarily didn't go bad but they weren't good either.  

            My first interesting fact is about the liquid that you get when you let it set for a period of time, it is alcohol from the fermenting yeast. My second interesting fact is the pineapple makes the process go by faster. This is because pineapple juice has the right ph to assist the fermentation process. When you keep a sourdough starter in the refrigerator you only have to feed it once a week because it keeps all of its yeast alive.    

My question is, why do you think a sourdough starter can go “bad?” This topic is important because it tell you where thing can go bad. It could even say were the better air for you is. Like being around fungi and plants is cleaner with the air you breath, and when you’re around chemicals it’s worse for you. 

Health in the Average Body by Nat

A body needs food in order to obtain a source of energy. The intestine is the way how food nutrients are absorbed. A way to having a healthy body is having balanced diet of carbohydrates, fruits, and vegetables. Also maintaining a low fat and sweets intake can help you achieve a balanced diet.

1.     Carbohydrates can be obtained through eating grains, breads and vegetables. The body uses carbohydrates to form cell structures and cell membrane. These things protect nervous tissue, and to provide as a source of energy.

      2.  Another essential food is fibers, found mainly in plants. Fibers are important in slowing down the digestive tract and preventing colon cancer.

      3. Vitamins are also important to the body system. Vitamins are trace elements that play a key role in supporting the body’s immune system and keeping cells healthy.

Question

What is the purpose in having two intestines for absorbing food?

Importance

The reason for having a small intestine is to absorb the nutrients and water. The small intestine also uses acids to break food into simple sugars. The large intestine moves out waste and compacts it into smaller particles. The proteins get broken down into amino acids. 

Alkaline Earth Metals by Caitlin

Alkaline earth metals are metallic elements located in the second group of the periodic table. They are extremely reactive, and because of this they are not found in nature. They have two electrons in their outer energy level. Alkaline earth metals are shiny, malleable, and ductile.

They have many uses, including being used in fireworks. They can also be used to make hand tools. Some of the alkaline earth metals provide nutrients to our bodies.

These metals are very important to our bodies and our ways of life. How do you think our world would change if we didn’t have any alkaline earth metals?