If one molecule is the same as another, we can call them the same chemical species. A chemical species is a type of chemical, like a single atom, an ion (which is an atom with an electric charge), or a molecule
They consist of two types : i) Cation ii) Anion
The formation of a sodium ion can be represented by a diagram as follows :
2. ANION: The anion are formed when an atom gains electron in the outermost shell and hence they posses the negative electric charge on it (which shows that the number of protons are lesser than the number of electrons).
Cl0 + 1 electron → Cl– ΔE= -VE
The formation of a chloride ion can be represented by a diagram as follows :
Molecular ions are formed when a molecule gains or loses electrons, resulting in a net charge. Molecular ions are represented in the same way as ions, with the charge indicated by a superscript. For example, the ammonium ion, NH4+, is a molecular ion.
Free radicals are molecules or atoms that have an unpaired electron. This makes them highly reactive and capable of initiating chemical reactions. Free radicals are often represented with a dot to indicate the unpaired electron, for example, the hydroxyl radical is represented as •OH.
Mathematically, the charge on an ion or molecular ion can be calculated using the formula:
Charge = number of protons – number of electrons
For example, the charge on the chloride ion (Cl-) is:
Charge = 17 (number of protons in chlorine) – 18 (number of electrons in chloride) = -1
Similarly, the charge on the sodium ion (Na+) is:
Charge = 11 (number of protons in sodium) – 10 (number of electrons in sodium) = +1
It is important to note that the number of protons in an atom or molecule (which determines its identity as a particular element or compound) does not change when electrons are gained or lost to form an ion.
In chemistry, a chemical equation is a symbolic representation of a chemical reaction. It shows the reactants on the left-hand side and the products on the right-hand side of the equation, separated by an arrow (→). The basic skeleton of a chemical equation consists of three main parts:
Reactants: These are the substances present at the beginning of a chemical reaction. They are written on the left-hand side of the arrow. Reactants are the substances that undergo a chemical change during the reaction.
Arrow: The arrow in the chemical equation points from the reactants to the products and indicates the direction of the reaction.
Products: These are the substances formed as a result of the chemical reaction. They are written on the right-hand side of the arrow.
The general format of a chemical equation is as follows:
Reactants → Products
For example, consider the reaction between hydrogen gas (H2) and oxygen gas (O2) to form water (H2O):
H2 + O2 → H2O
In this example, hydrogen gas and oxygen gas are the reactants, and water is the product. The arrow shows that the reactants are converted into the products during the chemical reaction.
Note: In a balanced chemical equation, the number of atoms of each element is the same on both sides of the equation. This ensures that the law of conservation of mass is satisfied, which states that mass cannot be created or destroyed during a chemical reaction. However, the concept of balancing equations is usually introduced in higher classes, and for 9th grade, the basic skeleton of a chemical equation is sufficient.
