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Chemical Bonds Section 2 - Types of Bonds Ionic Bonding To reach a stable energy level, atoms lose or gain electrons. An atom is neutral but will become a charged atom if there is a transfer of electrons When an atom loses or gains an electron, it becomes an ion. Ion – charged (atom) particle that has either fewer or more electrons than it has protons Ionic Bonding Negative ion – has more electrons than protons Positive ion- has more protons than electrons Ionic Bond bonding that involves a transfer of electrons forms when ions attract each other and form a compound force of attraction between a positive ion and a negative ion Electron-dot Diagram drawing that uses the chemical symbol for an element surrounded by a series of dots to show the electron bonding taking place. The dots represent the valence electrons also called Lewis Dot Structure/diagram Covalent Bonding A lot of energy is required for an atom to lose or gain electrons Example: elements in Group 14 have four electrons in their outermost level – it is easier for these elements to become stable by sharing electrons Covalent Bonding bonding in which electrons are shared rather than transferred The attraction between electrons and the positively charged nucleus of the atoms hold the atoms together Molecule A group of two or more atoms joined together by a formed by a chemical bond Unequal electron sharing Electrons are not always shared equally the nucleus of some atoms will attract electrons more strongly and electrons will stay closer to that atom’s nucleus Nonpolar and Polar molecules When two atoms that are exactly alike form a covalent bond, they share the bonding electrons equally. Nonpolar molecule, the electrons are shared equally in the bond When one atom’s nucleus has a stronger force, electrons will stay closer to that atom. Example: Water molecule H2O Water Molecule (cont) The oxygen atom forms a covalent bond with each hydrogen atom The oxygen atom has a stronger attraction for the bonding electrons – the electrons spend more time closer to the oxygen atom. This gives the oxygen atom a partial negative charge and the hydrogen a partial positive charge Water Molecule (cont.) Because the water molecule has an end that is partially positive and an end that is partially negative, water is a polar molecule. Polar means “having oppositely charged ends” **This polarity helps give water the structure to support life (cell systems)
"Chemical Bonds Section 2 - Types of Bonds"