Skip to main content

PERIODICITY OF PROPERTIES

PERIODICITY OF PROPERTIES:

                    Periodicity of properties refers to the repetition of similar properties of elements as we move across a period or down a group in the periodic table. This is due to the periodicity of the electron configuration of the elements.

                    The periodic table is a chart that organizes the elements by their atomic number, which is the number of protons in the nucleus of an atom. The elements are also arranged by their electron configuration, which is the way that the electrons are arranged around the nucleus.

                    The periodic table is divided into periods and groups. Periods are the horizontal rows in the table, and groups are the vertical columns. As we move across a period, the number of protons and electrons in the atom increases by one, but the electron configuration stays the same. This means that the atoms become larger as we move across a period, and their properties change.

                    As we move down a group, the number of electron shells increases by one. This means that the atoms become smaller as we move down a group, and their properties change.

Here are some of the periodic trends in properties:

Atomic radius:

                    Atomic radius decreases from left to right across a period and increases from top to bottom down a group. This is because as we move across a period, the number of protons and electrons in the atom increases, but the number of electron shells remains the same. This means that the electrons are held closer to the nucleus, and the atomic radius decreases. As we move down a group, the number of electron shells increases, so the electrons are held farther from the nucleus, and the atomic radius increases.

Ionization energy:

                    Ionization energy is the energy required to remove an electron from an atom in its gaseous state. Ionization energy increases from left to right across a period and decreases from top to bottom down a group. This is because as we move across a period, the atomic radius decreases, which means that the electrons are held closer to the nucleus and are more tightly bound. As we move down a group, the atomic radius increases, which means that the electrons are held farther from the nucleus and are less tightly bound.

Electronegativity: 

                    Electronegativity is a measure of an atom's ability to attract electrons. Electronegativity increases from left to right across a period and decreases from top to bottom down a group. This is because as we move across a period, the nuclear charge increases, which means that the atoms have a stronger pull on electrons. As we move down a group, the shielding effect of the inner electron shells increases, which means that the atoms have a weaker pull on electrons.

Metallic character: 

                    Metallic character increases from top to bottom down a group and decreases from left to right across a period. This is because as we move down a group, the number of valence electrons increases, which means that the atoms have a greater tendency to lose electrons and form positive ions. As we move across a period, the nuclear charge increases, which means that the atoms have a stronger pull on electrons and are less likely to lose electrons.



Comments

Post a Comment

Popular posts from this blog

PHOTOSYNTHESIS

Photosynthesis :                     Photosynthesis is the process by which plants use sunlight to convert carbon dioxide and water into oxygen and sugar. It is the foundation of the food chain and the basis for all life on Earth.                     Photosynthesis takes place in the chloroplasts of plant cells. Chloroplasts are small organelles that contain chlorophyll, a green pigment that absorbs sunlight. When sunlight hits chlorophyll, it excites the electrons in the chlorophyll molecule. These excited electrons then flow through a series of proteins called an electron transport chain. As the electrons flow through the electron transport chain, they release energy. This energy is used to pump hydrogen ions across a membrane. The hydrogen ions then flow back down the gradient, and this flow of ions generates ATP, the cell's main energy currency.     ...
Post a Comment
Read more

STATES OF MATTER

Physical States of Matter :                     Matter is anything that has mass and takes up space. It can be found in three different physical states: solid, liquid, and gas.                    1. Solids have a definite shape and volume. The particles in a solid are tightly packed together and vibrate in place. This is why solids have a fixed shape and cannot be easily compressed.                 2. Liquids have a definite volume but no definite shape. The particles in a liquid are still close together, but they are able to move around each other. This is why liquids can flow and take the shape of their container.                    3. Gases have no definite shape or volume. The particles in a gas are very far apart and move around very quickly. This ...
Post a Comment
Read more

PHYSICIAL QUANTITIES

PHYSICIAL QUANTITIES :                                                                        A physical quantity is a property of a material or system that can be quantified by measurement. A physical quantity can be expressed as a value, which is the algebraic multiplication of a ' Numerical value ' and a ' Unit '. For example, the physical quantity of mass can be quantified as '32.3 kg ', where '32.3' is the numerical value and 'kg' is the Unit. A physical quantity possesses at least two characteristics in common. Dimensions: A physical quantity has a certain number of dimensions, which are the basic units of measurement that are used to quantify it. For example, the dimensions of mass are length, mass, and time. Units: A physical quantity has a certain unit of measureme...
Post a Comment
Read more