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Answers to Readers' Questions on Chemistry:
Chemical Bonding
The following 9 comments and questions have been sent in. They are listed according to date.
List of first 10 items
- What is cation?
- Where does heat come from in exothermic reactions?
- Really helped me understand
- Concerning the maximum electrons in an orbit
- This site was a blessing for teacher
- Been studying Chemistry for Dummies
- What are the valence electrons of Copper?
- Break water into H and O
- Can Carbon and Silicon bond together?
What is cation?
Question
May 5, 2009
i really enjoyed the mini-quiz. i got one wrong but it was OK. Question: what is cation?
Madelein - Namibia
17703
Answer
I'm glad you enjoyed the mini-quiz.
An ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. A cation is an ion with a positive electrical charge.
Where does heat come from in exothermic reactions?
Question
November 6, 2007
Some reactions are exothermic, meaning they release heat. Why? Where does the heat energy come from?
Thanks,
Bill Biggers, on behalf of Grant Biggers, Age 10
The Next Great Scientist
Grant - USA
14719
Answer
In some chemical compounds, the atoms are held together but there is also a great potential energy that makes them want to separate. Such compounds are often unstable and easily broken down into individual atoms or stable molecules.
What happens in an exothermic reaction is that when the atoms separate in the molecule, it is like an explosion where the parts move apart quickly. This kinetic energy is translated into heat, which is actually the particles moving much faster than before.
Really helped me understand
Question
February 26, 2007
This really helped me understand chemical bondings. I really liked the commets the computer gave me when i answered a question on the mini-quiz right. For example: it said you really know your chemistry and you are really good looking to. that made me feel really special. it boosted up my self esteem a lot. THANK YOU VERY MUCH!!!!!
Kennyeh - USA
13259
Answer
I'm glad to hear that the material helped you understand chemical bonding. Keep up the good work. You have the potential of being a champion.
Concerning the maximum electrons in an orbit
Question
August 1, 2006
The maximum no. of electrons in the outermost orbit is denoted by 2xnxn. But the outremost orbit is deemed to be full with 8 electrons. Why this difference? Can you give examples of elements that have more than 8 electrons in the outermost orbit?
Thanks
girish - India
11593
Answer
When the outer orbit has 8 electrons, it is considered full in that the element is relatively inert. The noble gases each have 8 electrons in their outer orbits. But that is not the maximum number of electrons in an orbit. Other materials have higher numbers, since the orbit where the electrons are placed follows a complex formula.
If you look at the Periodic Table at: http://www.school-for-champions.com/science/chemperiodic2.htm and click on the various elements, you can see how many electrons they have in each orbit.
This site was a blessing for teacher
Question
January 9, 2006
Thank you so much for your very simple explanation of bonding. I am a science teacher in middle school and have been trying to find material that is simple enough for my students to enjoy and comprehend. This site was a blessing.
Do you have any more quizzes or tests?
Thanks
Patricia - USA
9610
Answer
I'm glad to hear that the material has been useful to you and your students. We plan to add more tests soon, as well as lessons in math.
Best wishes with continued success in your class.
Been studying Chemistry for Dummies
Question
December 11, 2005
I am a 72 year old male who has been studing "Chemistry for Dummies" during the past year. My questions are:
1.How many energy levels are there and what are their names?
2.Where can I find out the number of valance electrons for all of the
elements on the Periodic Table?
3. Using Uranium for example, where are those 92 electrons located ?
4. Can they really see the atom as described in the Quantum mechanical model ?
Thanks for your help and I enjoyed your quizs.
Al - USA
9347
Answer
You can find out much about the electrons and their levels from the Periodic Table. See:
http://www.school-for-champions.com/science/chemperiodic2.htm
Information on electrons is in the Shells box.
Ther have been "pictures" taken of atoms, but they really don't show much.
Best wishes in your studies.
What are the valence electrons of Copper?
Question
November 16, 2005
What is the valence electrons of Copper and Chromium?
maliviwe - South Africa
8969
Answer
Check the periodic table to find our how many electrons are in the outer orbits.
http://www.school-for-champions.com/science/chemperiodic2.htm
Break water into H and O
Question
March 15, 2005
How can you break the oxygen and hydrogen of plain water apart and contain them
Shawn - USA
6342
Answer
You can send electricity through the water (usually a salt solution) and collect the O2 on one wire in the water and H2 on the other.
For a desctription of the experiment, see:
http://www.haverford.edu/educ/knight-booklet/electrolysis.htm
Can Carbon and Silicon bond together?
Question
September 3, 2004
Is it possible for a Carbon atom and a Silicon atom to covalently bond together and form a new compound? Has it ever been done?
Carmena - USA
4165
Answer
A number of Carbon atoms have bonded to form molecules called "Bucky Balls." Since Silicon has the same outer orbit properties, it is possible that such a molecule could not be made of Silicon atoms. Also, a Silicon atom might replace a Carbon atom in a Bucky Ball.
As far as I know, this has not been done.
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