Electronegativity, Electron Affinity and the Types of Chemical Bonds

Atoms are held together by the interaction of the electrons. The type of electron interactions determine the way compounds are formed. These interactions form individual molecules or lattice structure crystals.

Technology Standards
Standard 1- Basic operations and concepts
Standard 2- Social, ethical, and human issues
Standard 3- Technology productivity tools
Standard 4- Technology communications tools
Standard 5- Technology research tools
Standard 6- Technology problem-solving and decision-making tools

Information Literacy
Standard 1- The student accesses information efficiently and effectively
Standard 2- The student evaluates information critically and competently
Standard 3- The student uses information accurately and creatively

Reside at the heart of the discipline
Helps the student understand the interactions of matter and energy.

Represents a big idea having enduring value beyond the classroom:
The way we experience things is determined at the molecular level.

Require uncoverage, meaning that misconceptions need to be identified and clarified:
Electronegativity and Electron Affinity are often confused. Though they have similar trends on the periodic table they represent different processes.
Offer potential for engaging students:
Elements are portrayed as doing battle for electrons.

Exit cards, class discussion and questioning, and a summative evaluation are all strategies that will be used in this unit. Exit cards will be used after the introduction of a new concept so that the instructor may evaluate the need for reteaching or redirecting the students. In class discussions the teacher should listen for statements that would indicate an incorrect understanding or misconception. The summative evaluation will be a performance task in which student will calculate bond polarity, predict bond type and rank compounds according to chemical and physical properties.

a. Introduction of Chemical Bonding- This will allow the students to become at ease with the terminology of chemical bonding through a brainstorm session followed by a time of categorizing concepts. This would occur in an exploratory class discussion format.

b. Different types of Chemical Bonds- This component is designed to provide information on the characteristics of ionic and covalent bonds in the form of note taking along with a lab activity that compares and contrasts the properties of compounds with ionic and covalent bonds.

c. Introduction of Electronegativity- This game is to help the students engage in an experience that parallels electronegativity in the elements. This activity is followed by a discussion of trends on the periodic table.

d. Using Electronegativity to calculate ionic character (bond polarity)- Electronegativity information will be utilized to calculate the ionic character of a particular bond.

e. Predicting Ionic and Covalent Characteristics- By utilizing previous notes and lab observations students will calculate percent ionic character for compounds and use them to make judgments about the type of bond formed. (Covalent, Polar Covalent, and Ionic)

f. Introduce Electron Affinity- Students will participate in a game to model this molecular behavior. `Electron Pickup' uses strength cards to see if elements gain or lose energy with an electron transfer. From this students can draw conclusions about the Electron Affinity trends on the periodic table.

g. The final component is performance task that asks students to predict bond types, calculate bond polarity and represent periodic trends in electronegativity and electron affinity.

Information Manager
Effective Communicator
Numeric Problem Solver
Creative and Critical Thinkers
Ethical and Responsible Workers
Resource Manager
Systems Manager
Cooperative Workers
Effective Leader