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Module 1 Intro

1. Module 1 Intro

1.9. Page 3

Module 1: Lesson 2

Module 1—Chemical Foundations

Ions

 

A diagram shows a black sphere surrounded by two circles. Below the diagram is the text upper case N, lower case e. Inside the black sphere is the text 10 p followed by a plus, and 10 n. The first circle surrounding the sphere has two small red spheres located at opposite sides of the circle. The second circle is larger than the first one and has 8 small red spheres equally spaced around the circle.

Current theories about the atom’s structure suggest that atoms have higher stability when their energy levels are filled to capacity with electrons.

 

Consider the noble gases. These elements are found in Group 18 on the periodic table and are known for their tendencies to be unreactive. As the theories you have studied to this point suggest, all noble gases have completely filled energy levels. For example, neon—which has 10 electrons surrounding the nucleus—has 2 electrons in the first orbital and 8 electrons in the second orbital. Both orbitals are completely filled. Because they are filled, neon is a stable gas and is very unreactive.

 

noble gas: elements listed in column 18 of the periodic table that share the property of very limited chemical reactivity



Discuss

 

Read “Formation of Monatomic Ions” on pages 23 and 24 of the textbook. After you have completed your reading, comment on the validity of the following statement:

 

“Atoms will gain or lose electrons to have an electron configuration like that of the nearest noble gas. When atoms gain or lose electrons, they become charged particles called ions. Energy level diagrams for ions can be drawn in a similar way as energy level diagrams for atoms. The difference is in showing a positive or negative charge on the ion.”

 

Write a brief comment about if you feel this is an accurate statement or not. Share your comment with your teacher.

 

Watch and Listen

 

You may wish to follow this Watch and Listen link to view the animation that reviews the formation of ions in a more in-depth manner. You may wish to try these Self-Check questions. Depending on your success, come back to this link before completing the other Self-Check questions.

 

Another explanation for the formation of ions appears in the “Audio Walkthroughs” section of Lesson 1.4 on the textbook’s website. If you do not already have access to this site, please contact your teacher.

 

Self-Check

 

SC 5. Draw the arrangement of protons, neutrons, and electrons for the phosphide ion.

 

SC 6. Draw the arrangement of protons, neutrons, and electrons for the beryllium ion. 

 

SC 7. Draw the arrangement of protons, neutrons, and electrons for diagrams for the following ions.

 

A drawing contains two rectangles. Each rectangle is positioned so that its longer side runs vertically. In the lower third of each rectangle is a circle. Below each of the circles is a label. The upper two-thirds of each rectangle is empty. The first rectangle has the label sodium ion. The second rectangle has the label sulfide.

 

Check your work.
Self-Check Answers

 

SC 5. Draw the phosphide ion. The phosphorus atom has 15 protons and 16 neutrons. In a phosphorus atom, the electrons are placed into three energy levels with 2, 8, and 8 electrons, respectively, from the innermost energy level to the outermost level. The phosphorus atom will gain 3 electrons to fill its valence orbital and become the phosphide ion. With this gain of electrons, the atom is no longer neutral; it now has 3 extra negative charges. This charge is included with the symbol as shown.

 

A drawing contains one rectangle. The rectangle is positioned so that its longer side runs vertically. In the lower third of the rectangle is a circle. Inside the circle is the text 15 lower case p superscript plus sign, and 16 lower case n. Below the circle is the text upper case P superscript 3 minus. Just above the circle is a horizontal line with the label 2 lower case e superscript minus. Above this line is a second and a third horizontal line labeled 8 lower case e superscript minus.

 

SC 6. The beryllium atom has 4 protons and 5 neutrons. It has 4 electrons placed in a 2-2 configuration. The beryllium atom will lose 2 valence electrons to become a beryllium ion. With this loss of electrons, the beryllium atom now has 2 extra protons compared to electrons. This shows up as a 2+ charge on the ion. Its electron configuration is now like helium, the nearest noble gas.

 

A drawing contains one rectangle. The rectangle is positioned so that its longer side runs vertically. In the lower third of the rectangle is a circle. Inside the circle is the text 4 lower case p superscript plus, and 5 lower case n. Below the circle is a text upper case B lower case e superscript 2 plus. Just above the circle is a horizontal line with the label 2 lower case e superscript minus.

 

SC 7.

 

A drawing contains two rectangles. Both rectangles are positioned so that their longer sides run vertically. In the lower third of the each rectangle is a circle. Below each of the circles is a label. The upper two-thirds of each rectangle is empty. The first rectangle has the label sodium ion. The second rectangle has the label sulfide.