Chemistry 7.1

Warm up: Please put your phones in the basket and get out a piece of paper and answer the following question. 1) How can I change my attitude/work ethic to make quarter two better for both myself and my classmates?

This quarter: We are going to switch class up a bit. From now on, when you turn your homework in, you will get a stamp with the date on it. If you are one day late, you lose 20%. If you are two days late, you lose 40%. Anything handed in after two days after the due date will not receive any credit. I will also do notebook checks periodically to make sure you are completing your homework. Keep in mind the respect rule applies from not on!

Today: You will start off by taking your first 20 elements portion of your chapter 6 test. I will give you 15 minutes to finish it, then we will take some notes over chapter 7.

Ions 7.1 Pyrite (FeS2), a common mineral that emits sparks when struck against steel, is often mistaken for gold—hence its nickname, “fool’s gold.” Pyrite is an example of a crystalline solid. In this chapter, you will learn about crystalline solids composed of ions that are bonded together. But first you need to understand how ions form from neutral atoms.

Valence Electrons Define valence electron. 7.1 Valence Electrons Valence Electrons Define valence electron. How do you find the number of valence electrons in an atom of a representative element?

7.1 Valence Electrons Valence electrons are the electrons in the highest occupied energy level of an element’s atoms. The number of valence electrons largely determines the chemical properties of an element.

7.1 Valence Electrons The number of valence electrons in an atom of a representative element is the same as its group number.

Review: Atoms of which elements tend to gain electrons? Metals Atoms of which elements tend to lose electrons? Nonmetals, metalloids, (not noble gases)

What is the octet rule?

7.1 The Octet Rule Noble gases, such as neon and argon, are unreactive in chemical reactions. In 1916, chemist Gilbert Lewis used this fact to explain why atoms form certain kinds of ions and molecules. He called his explanation the octet rule: In forming compounds, atoms tend to achieve the electron configuration of a noble gas.

7.1 The Octet Rule Atoms of metals tend to lose their valence electrons, leaving a complete octet in the next-lowest energy level. Atoms of some non-metals tend to gain electrons or to share electrons with another nonmetal to achieve a complete octet.

Next: Start on the homework – the 7.1 assessment, page 193 in your books. #3-11. If you don’t have your book, your may share with a classmate.

What is a valence electron? What is the octet rule? Bell Work: Please put your phones in the basket and answer the following questions on a piece of paper: What is a valence electron? What is the octet rule? You will need your textbooks today.

Next: Read pages 188-193 in your books and write the terms and definitions of the terms in bold. Then, you will have a worksheet to work on. I will give you 25 minutes to complete the reading and turn it in.

7.1 Formation of Cations Formation of Cations How are cations formed?

7.1 Formation of Cations An atom’s loss of valence electrons produces a cation, or a positively charged ion.

7.1 Formation of Cations The most common cations are those produced by the loss of valence electrons from metal atoms. You can represent the electron loss, or ionization, of the sodium atom by drawing the complete electron configuration of the atom and of the ion formed.

7.1 Formation of Cations The electron configuration of the sodium ion is the same as that of a neon atom.

7.1 Formation of Anions Formation of Anions How are anions formed?

7.1 Formation of Anions The gain of negatively charged electrons by a neutral atom produces an anion. An anion is an atom or a group of atoms with a negative charge. The name of an anion typically ends in -ide.

7.1 Formation of Anions The figure shows the symbols of anions formed by some elements in Groups 5A, 6A, and 7A. Atoms of nonmetals and metalloids form anions by gaining enough valence electrons to attain the electron configuration of the nearest noble gas. Interpreting Diagrams In which group of the periodic table do the elements bromine and iodine belong?

7.1 Formation of Anions A gain of one electron gives chlorine an octet and converts a chlorine atom into a chloride ion. It has the same electron configuration as the noble gas argon.

7.1 Formation of Anions Both a chloride ion and the argon atom have an octet of electrons in their highest occupied energy levels.

Please sit down and answer the following questions: Warm up: Please sit down and answer the following questions: What is the difference between a cation and an anion? What type of elements like to lose electrons? Which type likes to gain them? Anyone not sitting down when the bell rings in their assigned seat will be counted tardy. If you haven’t taken either portion of the chapter 6 test, you need to do so today or Monday.

What are electron dot structures What are electron dot structures? Write examples of typical electron dot structures.

7.1 Valence Electrons Electron dot structures are diagrams that show valence electrons as dots.

7.1 Formation of Cations Using electron dot structures, you can show the ionization more simply.

The sodium atoms in a sodium-vapor lamp ionize to form sodium cations. 7.1 Formation of Cations The sodium atoms in a sodium-vapor lamp ionize to form sodium cations. The sodium atoms in a sodium-vapor lamp ionize to form sodium cations (Na+). Applying Concepts How many electrons are in the highest occupied energy level of Na+?

7.1 Formation of Cations A magnesium atom attains the electron configuration of neon by losing both valence electrons. The loss of valence electrons produces a magnesium cation with a charge of 2+.

7.1 Formation of Cations Walnuts are a good dietary source of magnesium. Magnesium ions (Mg2+) aid in digestive processes. Walnuts are a good dietary source of magnesium. Magnesium ions (Mg2+) aid in digestive processes.

7.1 Formation of Cations Cations of Group 1A elements always have a charge of 1+. Cations of group 2A elements always have a charge of 2+. Cations of Group 1A elements have a charge of 1+. Cations of Group 2A elements have a charge of 2+.

7.1 Formation of Cations A copper atom can ionize to form a 1+ cation (Cu+). By losing its lone 4s electron, copper attains a pseudo noble-gas electron configuration.

7.1 Formation of Anions In this equation, each dot in the electron dot structure represents an electron in the valence shell in the electron configuration diagram.

7.1 Formation of Anions Oxygen is in Group 6A.

Write the Lewis Dot Diagrams for the following elements: B Cl O Ne Si Na Al Mg

Lets practice together! Next: What would be the electron configurations for the following atoms: Ca2+ N3- Na+ B3+ Zn2+ Mg2+ F- K+ I- S2-

Next: Please turn to page 199 in your books and start on the assessment. #14-22.

Please get out a piece of paper and answer the following questions: Bell Work: Please get out a piece of paper and answer the following questions: What does an electron dot diagram show? What changes about the electron configurations of ions? When you are done, hang on to them so you can take notes on the same piece of paper.

Use the paper you did your bell work on to take a few notes today. Next: Use the paper you did your bell work on to take a few notes today.

There are 2 rules for naming ions: Anion names end in –ide examples: Cl- is chloride ion S2- is sulfide ion Cation names keep the element name examples: Al3+ is aluminum cation Mg2+ is magnesium cation

All halogen ions are called halides 7.1 Formation of Anions The ions that are produced when atoms of Group 7A (halogens) gain electrons are called halide ions. All halogen atoms have seven valence electrons, and need one electron to achieve the electron configuration of a noble gas. All halogen ions are called halides

7.1 Formation of Anions

7.1 Conceptual Problem 7.1

7.1 Conceptual Problem 7.1

7.1 Conceptual Problem 7.1

Next: You have a worksheet to work on over naming ionic compounds. You will need to complete as much as you can in class because you will need it to do your homework which is found on the school website. I will also hand back your tests. If you don’t get yours, please come talk to me. There will be test corrections

Practice Problems For Conceptual Problem 7.1 Problem Solving 7.1 Solve Problem 1 with the help of an interactive guided tutorial.

7.1 Section Quiz. 7.1.

7.1 Section Quiz. 1. How many valence electrons are there in an atom of oxygen? 2 4 6 8

7.1 Section Quiz. 2. Atoms that tend to gain a noble gas configuration by losing valence electrons are metals. nonmetals. noble gases. representative elements.

7.1 Section Quiz. 3. When a magnesium atom forms a cation, it does so by losing two electrons. gaining two electrons. losing one electron. gaining one electron.

7.1 Section Quiz. 4. When a bromine atom forms an anion, it does so by losing two electrons. gaining two electrons. losing one electron. gaining one electron

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