Chemistry:
Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances. 

Topics in chemistry:

• Acids, Bases, and pH. …
• Atomic Structure. …
• Electrochemistry. …
• Units and Measurement. …
• Thermochemistry. …
• Chemical Bonding. …
• Periodic Table. …
• Equations and Stoichiometry

Acids, bases and salts

Characteristics of Acids, Bases & Salts. … Salts are a product of the reaction between an acid and abase. A common method used to determine an acidor a base is a litmus test, but there are other characteristics that can help you identify acids,bases and salts.

pH SCALE, ACIDS & ALKALI.

IN Chemistry one of things we learn is the pH scale.

pH- is a scale of acidity from 0 to 14. It tells how acidic or alkaline a substance is. More acidic solutions have lower pH. More alkaline solutions have higher pH. Substances that aren’t acidic or alkaline (that is, neutral solutions) usually have a pH of 7 .

Acids often taste sour,while alkali often feels soapy.