7 periods

Periodic table is organized by their valence electrons, atomic number and their atomic mass ( and also their reactivity/ groups and families). Periodic table lists their elemental symbol, atomic mass and their name.

The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass.

Why is the periodic table called the periodic table? It is called the periodic table because of the way the elements are arranged. You’ll notice they’re in rows and columns. The horizontal rows (which go from left to right) are called ‘periods’ and the vertical columns (going from up to down) are called ‘groups’.

The periodic table is the most important chemistry reference there is. It arranges all the known elements in an informative array. Elements are arranged left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass.

Scientists use the periodic table to quickly refer to information about an element, like atomic mass and chemical symbol. The periodic table’s arrangement also allows scientists to discern trends in element properties, including electronegativity, ionization energy, and atomic radius.

Mendeleev left gaps in his table to place elements not known at the time. By looking at the chemical properties and physical properties of the elements next to a gap, he could also predict the properties of these undiscovered elements. The element germanium was discovered later.

There are no gaps in the periodic table. Apparent gaps in the periodic table of elements are gaps between energy levels of valence electrons orbitals. The gap between hydrogen and helium is there because they have electons only in the s orbital and none in p, d or f orbitals.

The two certeria used by Mendeleev to classify the elements in his periodic table are:

• Atomic mass: elements are arranged in the order of increasing atomic masses.
• The formulae of the hydrides and the oxides formed by the various elements.

A period is a horizontal row of the periodic table. There are seven periods in the periodic table, with each one beginning at the far left. A group is a vertical column of the periodic table, based on the organization of the outer shell electrons. There are a total of 18 groups.

1 ) It is based on atomic number . 2) properties of elements.

Mendeleev’s periodic law states that; The physical and chemical properties of elements are a periodic function of their atomic weights.

In chemistry, periodicity refers to repeating trends in element properties on the periodic table. Basically, what this means is if you drop down a row (period) on the table and move across it, elements follow the same trend as other periods. Periodicity reflects Periodic Law.

The Periodic Law states that the physical and chemical properties of the elements recur in a systematic and predictable way when the elements are arranged in order of increasing atomic number.

Elements of the periodic table are arranged in order of increasing atomic number. The periodic law states “When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties.”

The difference between Mendeleev and Moseley periodic table is that Mendeleev periodic table is created based on the atomic masses of chemical elements whereas Moseley periodic table is created based on the atomic numbers of chemical elements.

1) The periodic law states that similar properties recur periodically when elements are arranged according to increasing atomic number. similar properties recur periodically when elements are arranged according to increasing atomic weight. similar properties are everywhere on the periodic table.

The modern periodic table is based on Moseley’s Periodic Law (atomic numbers). He suggested that instead of arranging elements in the ascending order of their atomic masses, they should be arranged in the ascending order of their atomic numbers. The number of electrons in an atom is equal to the atomic number Z.

The modern periodic law states that the physical and chemical properties of the elements are the periodic functions of their atomic numbers. Scientists arranged elements in increasing order of their atomic numbers from left to right across each row.

Periodic property : The physical and chemical properties of elements are related to their electronic configuration particularly the outershell configurations. The electronic configuration of valence shell of any two elements in a given period is not same. This is called periodic property.

Periodic Properties of Elements with Examples

• Atomic Radius: Atomic radius of elements decreases as we go from left to right in periodic table.
• Ionization Energy: Energy required to remove an electron from atoms or ions is called ionization energy.
• Electron Affinity:
• Electronegativity:
• Metal-Nonmetal Property:

Periodic Properties of the Elements

• Atomic Radius.
• Ionization Energy (ionization potential)
• Electron Affinity.
• Electronegativity.
• Metallic Character.
• Other Trends.
• Redox Potentials. Oxidation Potential. Reduction Potential.
• Uses in knowing the Periodic Properties of Elements.

Periodic trends are specific patterns in the properties of chemical elements that are revealed in the periodic table of elements. Major periodic trends include electronegativity, ionization energy, electron affinity, atomic radii, ionic radius, metallic character, and chemical reactivity.

Periodic Trends. Periodic trends, or periodicity, appear with remarkable accuracy for many physical and chemical properties. The following properties will be discussed: metallic nature, atomic radii, ionic radii, reactivity, atomic mass, atomic number, ionization energy/electron affinity and electronegativity.