This molecular orbital model can be used to explain why He2 molecules don’t exist. Combining a pair of helium atoms with 1s2 electron configurations would produce a molecule with a pair of electrons in both the bonding and the * antibonding molecular orbitals. The total energy of an He2 molecule would be essentially the same as the energy of a pair of isolated helium atoms‚ and there would be nothing to hold the helium atoms together to form a molecule. The fact that an He2 molecule is neither
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Dependencies and Network Diagram The network diagram is a schematic representation showing the sequence and relationship/ dependency of the tasks along with their duration. All the tasks‚ except the first and the last‚ are linked with at least one predecessor and successor to have a proper sequence of work. This logical dependency between the tasks will determine afterwards the duration of the project. There are four types of dependencies which define the relation between pair tasks Finish-to-start
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Food Web Diagram Sci/230 November‚ 2013 Desert Biome Food Web Diagram Food Web Diagram An ecosystem can be defined as a more or less self-contained function unit in ecology consisting of all abiotic and biotic
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mywbut.com Data Flow Diagrams (DFDs) 1 mywbut.com Specific Instructional Objectives At the end of this lesson the student will be able to: • • • Identify the activities carried out during the structured analysis phase. Explain what a DFD is. Explain why constructing DFDs are important in arriving at a good software design. • Explain what a data dictionary is. • Explain the importance of data dictionary. • Identify whether a DFD is balanced. Structured Analysis Structured analysis
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E-R Diagram Introduction:- In 1976 ‚Chen developed the Entity-Relationship Diagrams ‚a high-level data model that is useful in developing a conceptual design for database . An ER diagram is a diagram containing entities or “items”‚ relationships among them‚ and attributes of the entities . The E-R model is one of the best known tools for logical database design. Within the database community‚ it is considered a natural and easy-to-understand way of conceptualizing the structure of database.
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turning point for a lot of citizens‚ these issues still exist today‚ and it is not based on any particular people‚ but based on government boundaries‚ to still include racism‚ poverty‚ politics‚ and some forms of slavery. Back then‚ when this all began Abraham Lincoln had become the President. “Opening the address he stated: “I have no purpose‚ directly‚ or indirectly‚ to interfere with the institution of slavery in the states where it exists” (Civil War Politics and Racism). President Abraham Lincoln
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4 Solubility Equilibrium- Common Ion Effect INTRODUCTION: The common ion effect is another example of Le Châtelier ’s Principle in action.The common ion effect tells us that the solubility of an ionic compound is decreased by the addition to the solution of another ionic compound that contains one of the ions involved in the solution It is also responsible for the reduction in solubility of an ionic precipitate when a soluble compound combining one of the ions of the precipitate is added to the
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1. What is an Entity Relationship Diagram? An entity relationship diagram is a graphical representation of an organisation’s data storage requirements. Entity relationship diagrams are abstractions of the real world which simplify the problem to be solved while retaining its essential features. Entity relationship diagrams are used to: identify the data that must be captured‚ stored and retrieved in order to support the business activities performed by an organisation; and identify the data required
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Functional Decomposition Diagram An analyst first must understand an organization’s business functions before he or she can begin developing information systems. The functional decomposition diagram (FDD) is a business planning tool that depicts the hierarchy of business functions‚ processes‚ and subprocesses within an organization that are later described in detail using process models (chapter 6). The exercise of breaking down‚ or decomposing‚ the business functions into processes makes complex
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Using Data Flow Diagrams Data flow diagram is used by system analyst to put together a graphical representation of data processes throughout the organization. It depicts the broadest possible overview of system inputs‚ processes‚ and outputs. A series of layered data flow diagrams may be used to represent and analyze detailed procedures in the larger system. By using combinations of only four symbols‚ the system analyst can create a pictorial depiction of processes that will eventually provide
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