Lets take a element from the alkali metals , potassium , if we take potassium it is likely to lose its last electron from the valance shell as the electron positivity of potassium is very great.
Potassium has 19 protons thus if it loses one electron from its group of 19 electrons it becomes disequilibrium , -18 electrons which makes potassium have a positive ion , + 1 net charge
Lets take an element from halogens , halogens are very reactive due to its electronegativity , atoms from halogens are very good absorber of electrons , lets take fluorine which has 9 electrons , 2 , 7 , when there is potassium and fluorine , potassium loses one electron while fluorine takes it due to its electronegativity thus potassium will become the positive ion while fluorine will become a negative ion
When potassium become positive and Florine become negative they attract due to electromagnetism thus they become KCI - Potassium chloride
Thus potassium chloride becomes neutral , equilibrium
Covalent bonds and molecules
A covalent bond is formed when two atoms share electron pairs. In a covalent bond, the stability of the bond comes from the shared electrostatic attraction between the two positively charged atomic nuclei and the shared, negatively charged electrons between them.
When atoms combine by forming covalent bonds, the resulting collection of atoms is called a molecule.
We can therefore say that a molecule is the simplest unit of a covalent compound.
As we will now see, there are a variety of different ways to represent and draw molecules
Representing molecules: chemical formulas
Chemical formulas, sometimes also called molecular formulas, are the simplest way of representing molecules. In a chemical formula, we use the elemental symbols from the periodic table to indicate which elements are present
We use subscripts to indicate how many atoms of each element exist within the molecule. For example, a single molecule of NH , ammonia, contains one nitrogen atom and three hydrogen atoms.