Elements of periodic table

• Elements with similar properties occur together on the periodic table.
• The elements are arranged according to their atomic number, which is the number of protons in an atom.
• Atomic mass is not used as a basis for arranging the elements because it can vary depending on the presence or absence of neutrons.
• The first row of the periodic table contains only two elements - hydrogen and helium.
• Atomic mass is determined by adding up the masses of all the particles that make up an atom (protons, neutrons, electrons).
• The elements are arranged according to their atomic number, which is the number of protons in an atom's nucleus.
• Groups (columns) contain elements that have similar chemical behavior due to having the same number of electrons in their outermost shell.
• Metals have high melting points and boiling points compared to non-metals.
• Metalloids (also known as semi-metals) have intermediate physical properties between those of metals and non-metals.
• Hydrogen has one electron and one proton, while helium has two electrons and two protons.
• Nitrogen has seven electrons and seven protons, while oxygen has eight electrons and eight protons.
• Boron has five electrons and five protons, while carbon has six electrons and six protons.
• Lithium has three electrons and three protons, while beryllium has four electrons and four protons.
• The periodic table arranges elements based on their atomic structure and properties.
• Elements can be classified into different groups based on their physical and chemical properties.
• Metalloids are found between metals and non-metals and exhibit both metal and non-metal characteristics.
• Non-metals are located to the right of the periodic table and do not conduct electricity or heat well.
• Periods or rows contain elements that increase in atomic radius and decrease in metallic character.
• Metals are found at the left side of the periodic table and have metallic bonding.
• Potassium has nineteen electrons and nineteen protons, while calcium has twenty electrons and twenty protons.
• Electron configuration describes how electrons are arranged around the nucleus of an atom.
• Atomic structure refers to the arrangement of particles within an atom.
• Mass number is the sum of protons and neutrons in an atom's nucleus.
• Atomic number is the number of protons in an atom's nucleus and determines its identity as an element.
• Alkali metals (Group 1) have one valence electron and react vigorously with water to form hydrogen gas and alkaline solutions.
• Transition metals have partially filled d orbitals and exhibit unique properties such as catalytic activity and colorful compounds.
• Groups or columns contain elements with similar electron configurations, which determine their chemical behavior.
• Noble gases are unreactive and exist as single atoms.
• Non-metals tend to form negative ions when they gain electrons.
• Halogens are highly reactive and form compounds with other elements by gaining an electron.