Chemical Bond Flashcards
2 types of chemical bond
Ionic
Covalent
Ionic bond
Atom accepts or donates one or more valence electrons to another atom
Covalent atom
Atoms share valence electrons
If the electronegativity values of two atoms are similar
Metallic bonds form between two metal atoms
Covalent bongs form between two non metal atoms
….non polar when electronegativity very similar
….polar when are little further apart
If the electronegativity values of the two atoms are different
Ionic bonds are form
Electronegativity
Property of an atom which increases with its tendency to attract the electrons of a bond
Octet rule
Octet rule
Elements gain or lose electrons to attain an electron configuration of the nearest noble gas
Why do elements follow the octet rule
Because they always seek the most stable electron configuration
Results in completely filled s- and p orbitals in an atom’s outermost energy level
Los atomic weight elements
First 20 elements
Adhere the octet rule
Theory of chemical bonding
3
Why atoms form bonds
Stability
Energy
Octet rule
Why molecules have an specific geometry?
VSEPR
Why compounds have an specific chemical formula
Valence electrons
Chemical bonds 3 types
Ionic electrostatic attraction between ions
Covalent sharing of electrons
Metallic metal atoms bonded to several other atoms
Covalent bonding 3 electrostatic interactions
Attractions between electrons and nuclei
Repulsion between electrons
Repulsions between nuclei
Properties of ionic compounds
Form crystals
Have high melting point and boiling point
Hard and brittle
Conduct electricity when they are dissolved in water
Ionic solids are good insulators
Types of covalent bonds
Polar
No polar
Polar
Electron is more attracted to one atom than to another
Greater the difference in electronegativity the more polar is the bond
Properties of covalent(molecular) compounds
Most have relatively low melting points and boiling point
Soft and flexible
More flammable
Dissolve in water don’t conduct electricity
Don’t dissolve well in water
Co-ordinate bonding
Also as dative covalent
Is a covalent bond in which both electrons come from the same atom
CO
H2SO4
Electron sea model
Metallic bonding in which cations are considered to be fixed points within a mobile sea of electrons
Basic metals
Right of the transition metals
