A chemical symbol is a one-or two-letter notation that represents an atom in a chemical element. 

In the analysis of elements, a symbol is quite important. For example, the symbol Cl stands for chlorine: the chemical element. A single atom of chlorine has an atomic mass of 17 a.m.u.

The valency of an atom or radical refers to its ability to combine with other atoms or radicals. The number of hydrogen atoms that can join with or displace one atom of the element or radical is known as valency. 

• Metals are electropositive by composition and must surrender electrons to achieve the octet structure. Group 1 (alkali metals) metals are univalent and contain only one valence electron. 
• Group 2 metals (alkaline earth metals) are divalent and have two valence electrons. 
• Group 3 metals are trivalent, meaning they have three valence electrons.
• Non-metals are electronegative by composition and therefore gain electrons to achieve octet configuration. 
• Four valence electrons are present in carbon, silicon, and other groups of four elements. They are called tetravalent compounds. These elements achieve octet configuration by sharing electrons with one or more other elements under normal conditions.

1. When two or more molecules combine to create a new substance, it is called a chemical reaction. 
2. Reactants are substances that combine to create new compounds, whereas products are the freshly created compounds. 
3. Chemical reactions are essential in a variety of industries, processes, and even our daily lives. They are constantly occurring around us, such as rusting of iron, pottery, and wine fermentation, to name a few. 
4. A chemical transition must result in a chemical reaction and is commonly observed in physical adjustments such as precipitation, heat generation, colour change, and so on. 
5. A reaction may occur between two atoms, ions, or molecules, in which they build a new bond without destroying or creating an atom; however, a new substance is produced from reactants. 
6. The rate of reaction is influenced by factors such as strain, temperature, and reactant concentration.

There are some significant features of a chemical reaction’s occurrence:-

1. Changes in chemical composition
   The nature and function of a material shift occur due to chemical reactions, which results in a specific chemical transition. Heat may either be emitted or consumed. In the end, new substances are formed.
   
2. Conditions
   A chemical reaction may only take place where the temperature and pressure are about right. If the conditions aren’t correct, the reaction won’t happen.
3. Products
   Only when the compounds produced are similar to the reactants will a chemical reaction be identified. The latest products are created, which vary from the initial reactants in certain waysChemical equations are symbolic descriptions of chemical reactions that express the reactants and products in their chemical formulae. Symbols are used to represent things like the reaction’s trajectory and the responding bodies’ physical states. In the year 1615, the French chemist Jean Beguin was the first to devise chemical equations. With the help of chemical equations such as the one seen below (for the reaction between hydrogen gas and oxygen gas to form water), chemical reactions can be written. 

   2H₂+O₂→2H₂O

   The responding entities are written on the chemical equation’s left-hand side, whereas the compounds produced by the chemical reactions are written on the right-hand side.

   It’s also worth noting that each of the symbols for the respective reactants and products has a coefficient associated with it. The precise value of stoichiometric number for each individual is represented by the coefficients of entities in a chemical equation.

In this chapter, we learned how chemistry is represented. We learned about the Chemical Reactions & Equations and their occurrence.

1. What are chemical equations? And how do they work?
   Chemical formulae and symbols are used to describe chemical processes in these equations. The reactants are on the left-hand side of a chemical equation, while the components are on the right-hand side. An emblem that represents the reaction’s trajectory separates these bodies. The stoichiometric coefficient for each reacting object is often allocated.
2. What are the four different kinds of chemical reactions?
   Synthesis, decomposition, single replacement, and double replacement are the four basic chemical reactions.
3. What is the chemistry language?
   The terms symbol, equation, ion, valency, atom, particle, molecule, reaction, and so on are all used in chemistry.
4. What distinguishes the chemistry language from other languages?
   Prediction, asking, explanation, visualising, and summarising are some of the aspects.
5. What is chemistry?
   Chemistry is the study of the properties, composition, and structure of substances (defined as elements and compounds), as well as the transformations and energy produced or absorbed during these processes.