LESSON PLAN ON ALKALI METALS
April 25, 2000
General Chemistry/Chemistry I
10th-11th grade - 30 students
Instruction Time - 1 hour
II. RATIONALE AND BACKGROUND
The purpose of this lesson is to introduce students to the alkali metals found in group 1 on the Periodic Table of the Elements. The basic facts will be given for each of the six alkali metal elements: the atomic number, the atomic weight, color, boiling and melting points, chemical symbol used, general facts about each element and what they may look like and what they may be used for or where they are found. This is a general overview for these six elements. Students will be able to see two of the alkali metals first hand with the teacher doing an experiment, while the students watch, on the slicing of a piece of sodium and also exposing a piece of potassium and sodium in water to show some of the chemical properties of this class of metals. A power point presentation will be used for the general note-taking part of the lecture.
Students will have sufficient background knowledge of the terms atomic number, weight, boiling and melting points, the reason a chemical symbol is used and what the Periodic Table is and what type of information can be found on the Periodic Table. The students understand general behavior rules for work in the lab or while teacher presentations/experiments are being held in the lab. The students also have sufficient note taking skills to take adequate notes on this introductory lesson.
III. LESSON OBJECTIVES
1. TLW (The learner will) be able to name the six alkali metals, their chemical symbols, their atomic numbers, and know their location on the Periodic Table of the Elements.
PI: (Performance Indicator) At the end of the week, the students will take a short quiz on the alkali metals asking their location on the Periodic Table, their chemical symbols, and their atomic numbers. Students should be able to achieve at least 20 points out of a possible 25 on this quiz for average level work.
2. TLW describe one general fact for each of the alkali metals. This includes choosing a fact from where they are found, what they are used for, when they were discovered, how they were named, or their Latin root word.
PI: On the short quiz that the students will take at the end of the week, they will have a space to write one fact that they know about each of the six elements that they learned in class.
IV. RESOURCE MATERIALS
*Microsoft Power Point Presentation software
*projector for power point presentation and screen
*access to the internet for online information regarding the six alkali metals
*access to pure sodium and potassium metal for teacher presentation
*safety goggles and apron
*large 2-gallon beaker or container
*chemist's gloves to prevent burning during the dropping of the Na/K in H2O.
There are six Alkali Metals found on the Periodic Table in Group I that are represented by their malleable and ductile chemical properties.
They are softer than most of the metallic elements found on the Periodic Table. They don't really carry the same properties as most of the other metallic elements.
They are all highly reactive elements and can explode if they are exposed to water.
They do not occur freely in nature and are very reactive, with one electron in their outer shell making them easier to combine with other elements to make compounds.
A. Introduction and Motivation
Starting the Power Point presentation, students will see a colorful screen in front of them with the words, Alkali Metals, in front of them and a dance-type song being heard in the background to get their attention and to interest them.
Teacher will ask questions about the alkali metals to students to see if students have been reading their textbook or have heard about them in other classes to get them interested in the topic and to see the general knowledge of the class from the start.
After a short question and answer session on the introduction of the Alkali Metals, teacher moves on to the actual Power Point presentation and the note-taking part of the class starts.
B. Lesson Body
Group I on the Periodic Table: Alkali Metals
T: (Teacher) Now everyone knows what the Periodic Table is and what type
of information is found on it, right? Ok, so we talked about other classes of elements found on this chemical table, so we're going to add another to our general knowledge. This new group of elements is found in the first column or row down the left side of the table in Group 1. Who remembers what direction the Groups go on the Periodic Table? From top to bottom, right! The group of elements found in Group 1 is called the Alkali Metals.
Has anyone heard of the Alkali Metals before? How many elements compose this group of elements? What makes these metals different from the rest of the metallic elements? Ok, well, we're going to take a look at the six Alkali Metals that make up group 1 on the periodic table today. Ready?
Teacher then begins Power Point presentation. The presentation consists of slides on each different element. Each of the six elements has 3 slides relating to their properties, information, and what they look like. The first slide for each element introduces the students to the name of the element, the chemical symbol of the element, its atomic number, atomic weight, color, melting point, boiling point, characteristic, and Latin root word that made up the name of the element. Then, a general characteristic of the element is given as the last item on the first slides, like how it might be the most reactive of the six elements or how it can be cut with a knife explaining how soft the element may be.
The second slide for each element shows a picture of the actual element and its Bohr model showing the configuration of the electrons in each of its shells and how many neutrons and protons each element has in its nucleus. If a picture of the element can't be found on the web or in a book, like possibly for francium, cesium, and rubidium, then the Bohr Model is the only thing shown on the elements second slide.
The third slide of each element can switch back and forth between telling the students what the element is used for, where it is found, or who discovered it, or even how it was discovered. This is the facts and information slide for each element. This is where the students will get their fact from for the quiz and later, the test on the unit.
After the Power Point Presentation is finished, remind the students of a short quiz on this topic at the end of the week and to begin studying.
Teacher Presentation with Sodium and Potassium metals
This presentation will be done in the lab with safety goggles and an apron being worn by the teacher. The students will need to only wear safety goggles. A protective glass or plastic shield should be put around the two-gallon water container being used for the reaction of the two metals when exposed to water.
First, using a knife, the teacher will put the knife, in the each of the jars and will slice a piece of sodium and potassium off to show how soft these metals are compared to the other metals on the Periodic Table. Then, the teacher will take that piece of sodium and potassium, one at a time, using tongs, and will place the pieces in water to show the reaction of each of the metals when exposed to water. This is where safety goggles should definitely be on and the teacher should be wearing protective gloves to protect against burning the hands in case of any splash of the Na/K and water on the hands or forearms.
After this presentation is done, students will return to their desks in the classroom. They will then be asked some general facts of the lesson today to see if they retained any of the information given in class today. After this short question and answer session, students will be allowed to pack their book bags and get ready for the bell to ring, signaling the change of classes.
A. Student Assessment
1. Assessment Plan
Students' understanding the concepts taught in class on the Alkali metals will be assessed during a short quiz at the end of the week pertaining to material taught in class and will again be later assessed during the unit test at the end of the unit.
Students will also be assessed in their behavior during the lab presentation done by the teacher and also their cooperation during the in-class note-taking session.