Types of chemical compounds Two types of chemical compounds: Ionic (electrolyte) Covalent (molecular) The type of compound will determine its properties Conductivity- ability to conduct an electrical current Substances that will dissociate into ions when dissolved in water is called an electrolyte Melting point- temperature at which a solid melts Solubility- ability to dissolve in a solvent (water). Boiling point- temperature at which a liquid turns to gas

Ionic Compounds Ionic Compound-compounds such as sodium chloride (NaCl) in which positive and negative ions attract each other to keep matter together. Properties of Ionic Compounds: They are hard and brittle They are solid at room temperature They have very high melting points They conduct electricity if heated to a liquid state They conduct electricity when dissolved in water

Ionic Compounds Ionic bond- attraction between oppositely charged ions, occurring with all nearby ions with opposite charge. Ions are formed when a non-metal atom pulls an electron away from a metal atom, often referred to as “electron transfer”. The metal atom that loses an electron becomes a cation, and the non metal that gains an electron becomes an anion. Both atoms become stable.

Covalent Compounds Covalent compound- compound made up of molecules, called a molecular compound Properties of molecular compounds: Solids are hard and brittle, but others are soft and mushy Can be a solid, liquid or gas at room temperature Boiling/melting points vary, When melted or dissolved in water, they don’t conduct electricity well. Each water molecule is held to another molecule by a special type of attraction called a hydrogen-bond.

Molecular (covalent) Compounds Covalent bonds- the chemical bond that results from sharing valence electrons Electron sharing occurs between non-metal atoms A pair of electrons between atoms represents a single chemical bond The nucleus of one atom attracts the electrons of the other atom and visa versa Electrons are shared so that each atom has 8 electrons in its valence shell. Water Glucose

Learning Check What are the two types of chemical bonds? What properties of a compound are determined by the type of bond between atoms? Which type of compound is made up of positive and negative ions attracted to each other? Which type of compound is made up of molecules? Which type of compound conducts electricity when dissolved in water? Which type of compound can be either a solid, liquid or a gas? Which type of chemical bond is formed due to a transfer of electrons? Which type of chemical bond is formed due to electron sharing?