Look how mich points im giving away!
i need a brief summary and or paragraph on corrosion

A broader definition of corrosion is the destructive attack on a metal through interaction with its environment. It is the process by which metallic atoms leave the compounds in the presence of water or gas. Metal atoms leave the metal until it fails or erodes from oxidation.
The tendency for oxidation is dependent on the metal. Metals used in construction, such as steel and copper alloys, are both subject to corrosion. Metals are chemical combinations of multiple elements. These metals are highly vulnerable because of the high energy content of the elements used in metallic form. The energy content is higher than that of their ores, allowing corrosion to become a natural process. Through being present in their natural environments, the ores in the metal revert back to their original form. For example, iron in moist air becomes iron oxide.
The resulting rust is a generic term for when iron corrodes. The reaction between iron and water causes rust to form on a metal object.
I hope this helps you!

Answer trigonal pyramidal;

According to arrhenius theory of acid and bases, an acid is a proton donor, while base donates hydroxyl ions. further, acid and base reacts to form salt and water.consider following example.hcl    +      h2o          →      cl-          +      h3o+here, hcl has donated a proton, hence it is an acid.now consider following reactionhcl      +      naoh            ↔      nacl      +        h2oin this reaction, hcl donates proton, hence it is acid. on other hand, naoh donates hydroxyl ion (i.e. hence it is a base.