Current Event 2

                                                Bandages that could bite back
                                                Stephen Ornes
                                                May, 19th, 2010 http://en.longood.net/news_detail/newsId=2cf5f7e7-f91f-43a2-9d94-cd98253dfbd9&comp_stats=comp-FrontNews_list01-001.html

Has your skin ever been seriously burned? Were you struggling to find out how to make it stop being so excruciating? I certainly think so, because I felt the pain a few months ago.
Maybe there is no way that burns can stop hurting our skin (unless we don't drink some medicaments) But, there might be a way that the infections caused through the burns can be stopped!!
This article talks about a recent study showing how scientists (Jenkins) disovered a new type of bandage that could fight infection in your skin that passes the burns. In the bandage are found tiny capsules. To dangerous bacterium, these capsules look like tiny cells waiting to be destroyed. But what this bacteria doesn't know is that the capsules contain antibiotics, which kill the dangerous bacteria, and mkaes the skin perfect again!
When we are putting a normal bandage on our skin, the bacteria releases toxins (poison), but when we put this new invented bandage, it fights back, releasing antibiotics, as I said. This can be seen from the picture below.

 In this article, I read an interesting part of how they tested this out: They used two types of harmful bacteria (Staphylococcus and Pseudomonas) and put it with bandages Petri dish, and it didn't grow at all! This was very unusual. Even to me! They then repeated it with another type of bacteria (E . coli ) and they found similar results! However, they have to test out the real situation: They have to put the new bandage on real people's burnings! If this works, it will help a lot of people in fighting againts the burned infections.

The first thing that attracted me to this article was the picture of tiny capsules releasing the antibiotics while the bacteria attacks them. Bacteria released toxic compunds that's breaking the membrane and it's releasing another compund - antibiotic that kills bacteria! So, there are compunds, containing atoms (or elements) and that's it- everything is related to chemistry!!! :)

                                                                                                                                       Jovana Curcic 8B
                                                                                                                                   September 19th 2011

                                       How big is an atom and why do the sizes of atoms vary?

The size of atoms varies depending on their atomic mass (or how many protons, neutrons and electrons they have). My first hypothesis was that with an increase of the atomic mass, its atomic radius will increase too. But when I did my research have concluded the following:

-       WHEN WE LOOK AT THE PERIODIC TABLE,  FOR EXAMPLE IN THE SECOND PERIOD, WE WILL SEE THAT STARTING FROM LITHIUM TO FLORINE OUR ATOMIC # WILL INCREASE, BUT THE ATOMIC RADIUS WILL DECREASE. THAT’S BECAUSE WHEN THEY HAVE MORE PROTONS AND ELECTRONS, THE ATTRACTION BETWEEN THEM IS MUCH STRONGER AND IT SQUISHES THEM TOGETHER. (That can be seen in the graph below, number 3 to number 10.

-       THERE IS A BIG JUMP IN THE ATOMIC RADIUS BETWEEN THE NUMBERS 10 AND 11^TH ELEMENT (NEON AND SODIUM) BECAUSE WE ARE GOING FROM 2^ND TO 3^RD PERIOD, SO NOW WE HAVE 3 SHELLS, AND OUR ATOM IS BIGGER. HOWEVER, CURRENTLY WE HAVE THE SAME CASE AS IN THE SECOND PERIOD, AND SO ON…

I drew the graph in excel using data from this source: http://www.google.rs/imgres?imgurl=http://www.standnes.no/chemix/periodictable/atomic-radius-table.gif&imgrefurl=http://www.standnes.no/chemix/periodictable/atomic-radius-elements.htm&h=452&w=641&sz=20&tbnid=VaXUvRQHQazVsM:&tbnh=90&tbnw=128&prev=/search%3Fq%3Datomic%2Bradius%26tbm%3Disch%26tbo%3Du&zoom=1&q=atomic+radius&docid=_39B7LrTjCGJYM&hl=sr&sa=X&ei=MGJ3TuiMA8OP4gSTxaC5DQ&ved=0CDIQ9QEwAQ&dur=165

Everything I have explained about can be seen from the picture:

Atoms are neutral particles; they have the same number of electrons and protons so they have no charge. At times when an atom has more protons or more electrons, it becomes a positive ion or cation, and when it has more electrons it becomes a negative particle or an ion. It depends on its electron configuration (how many electrons it has and how they are arranged) whether an atom will become a positive or a negative ion. The Ionic radius will be bigger or smaller than the atomic radius depending on the facts that if we have a positive or negative ion. If you add an electron and the particle becomes negative, its ionic radius will be bigger than the atomic radius (because the attraction between the nucleus and these electrons will be weaker). If we have more positive particles (if we have a positive ion) we will have a smaller ionic atom (because we will have a bigger attraction). I think that this can be seen from the graph below that I did on excel using data from this site: http://www.webelements.com/periodicity/radius_ionic_pauling_1/

Current Event 1

                                                           Like poison for Phosphorus
                                                       Article written by: Stephen Ornes
                           http://www.sciencenewsforkids.org/2010/12/like-poison-for-phosphorus/

"CHNOPS"
This is not te secret code for some game entry - this is the abbreviation for the 6 crutial elements found in every living form.
But, the scientists from NASA's Astrology Institute found out that some kind of bacteria can live without even one of them - The bacteria from Monolake (Which is located in California) could live without phosphorus!Instead of this important element, the scientists fead this bacteria with arsenic (which is found to be poisonous for living organisms) and this bacteria survived. Although a lot of scientists are skeptic, with the result of this research, this investigation is very important for some astrobiologists  that say that this is a very big finding because it can show that the life on other planets can exist in other forms than on Earth.

I think that this article was very interesting because I learned some of the most important 6 elements in life and I have also learned about Phosphorus, which I will describe below:

1) It is a very sturdy element for all life forms (Or not for all?)
2) It is found in DNA (Important molecules of nucleic acid connected with genetic informations in the cell)
3) It is found in teeth, bones, etc...
4) Phosphorus is one of the main cources of energy for all living things (usually found as a ATP molecule)

Beside all of these facts I leanred, I have noticed that there is doubt of other researchers that are connectedwith this ivnestigation. I have wondered what would be if they didn't use this specific bacteria but some other organism? We will find out what will be in the future.

The Periodic Table of Elements

This is a picture of the Periodic Table where the metals + non-metals are highlighted.