![periodic table with valence electron charges periodic table with valence electron charges](https://i.pinimg.com/736x/d2/05/0e/d2050e3a2c5190aec9a1783eb8914e64.jpg)
![periodic table with valence electron charges periodic table with valence electron charges](https://iperiodictable.com/wp-content/uploads/2020/12/Periodic-Table-with-Charges.png)
The electrons occupy regions of space whichsurround the nucleus. We know protons andneutrons are make up the nucleus, but electrons are locatedoutside the nucleus. Theelectrons are located outside the nucleus. Although we have talked about the number ofelectrons in an atom we have not done much beyond that. These numbers of electrons appear to lend extra stability,i.e., the element does not like to react with other elements. In fact no knowncompounds containing helium or neon have ever been formed! Whatis so special about the noble gas elements? They appear to have aspecial number of electrons. Noble gases are very interesting, why?, because they donot react with very many other elements. Metals and nonmetals tend to lose or gain electronsto attain the same number of electrons as the nearest noble gaselement. So how do we know howmany electrons are lost or gained? This is a little moreinteresting.
![periodic table with valence electron charges periodic table with valence electron charges](https://i.pinimg.com/originals/71/d1/65/71d165dc58bd22a19163914742eb3e3a.gif)
When a metallic element and a nonmetallicelement react to form an ionic compound the metal loseselectron(s) and nonmetal gain electron(s). We started this discussion with theperiodic table, now it is time to return. So now we know what an ionic compound 'looks'like at the atomic level, how do ions form? What causes anelement to lose or gain electrons? And how many elecrons aregained or lost by an element? The real gory details are beyondthe scope of this class so we'll limit our discussion to thetrends that are observed. Notice thespheres (ions) of different sizes and how each sphere (ion) issurrounded by the other spheres (ion). Belowis a picture of a model of a simple ionic compound. What ever pattern which arises depends on several factorswhich we will not be discussing at this point in our class. In the state the spheres (ions) are arranged sothat any particular ion is surrounded by the oppositely chargedion. Here is a model of an ionic compound like sodium chloride.Ī simple model to be used to imagine what ions(cations or anions) look like at the atomic level, is a sphere.For simple monoatomic ions and most polyatomic ions we can thinkof as charged spheres of different sizes. Chemists have discovered thationic compounds almost always contain an element from a metallicgroup and at least one element from the nonmetallic group.
![periodic table with valence electron charges periodic table with valence electron charges](https://www.scienceabc.com/wp-content/uploads/2017/10/Periodic-table.jpg)
Ions that have moreelectrons than they have protons are called anions, while ionswith fewer electrons than they have protons are called cations.Cations and anions get together to form an ionic compound suchthat the total positive charge on the cation(s) equals the totalnegative charge on the anion(s). Ionic compounds are characterized by the fact that they arealways solids (there are some interesting exceptions to this rulethat have recently been discovered) and have high melting points.They are called ionic compounds because they are composed ofions. The two groups of compoundsare called ionic compounds and covalent compounds. Elements in the periodic table combine to form compounds.Chemists have classify compounds into two general groups, againbased on their physical properties. Here is a periodic table with the metals in blue, nonmetalsin yellow and the metalloids in.what is that color.between themetals and the nonmetals. Finally, if an element belongs to the metallic group it cannot be in any of the other groups. Needless to saythese elements can not make up their minds! Interestingly enoughthe metalloids are found exactly between the metallic elementsand the nonmetallic elements. The last group of elements are intermediate in theirproperties, some of their properties suggest metallic character,other properties suggest nonmetallic character. Thenonmetallic elements are characterized by their range of phases.Nonmetallic elements can be solid, liquid or gas phase.Nonmetallic elements do not conduct electricity very well(although one of the nonmetallic elements can). Another group of elements is called the nonmetals. They are shiny, malleable (canbe easily hammered into a shape), ductile (can be easily drawninto a wire), have a high melting point (that is why they aresolids!) and are able to conduct electricity. The metallicelements are characterized by their solid phase (although thereis one metal which is a liquid). One group of elements is called the metals. One way breaksthe periodic table into three groups. Chemistsseparate the elements a variety of different ways. The Periodic Table! The Periodic Table lists all of the known elements. Sohow to get started, the best way is to reveiw some things we havealready talked about. My goal is going to be todevelop an idea of the three-dimensional shape of compounds.Shape is an important feature in organic chemistry (carboncompounds) an area we are going to discuss in a week or so. In this next section of the class I' In this next section of the class I'm interested in exploringchemical compounds in more detail.