Periodic Classification and Elements

Yes, it is correct. It was based on both physical and chemical properties of the elements.

Carbon has 4 valence electrons in its outermost shell, which allows it to form 4 covalent bonds with other atoms. This property makes carbon the foundation of organic chemistry.

In the periodic table, 'He' is the chemical symbol for helium, a noble gas. Hydrogen's symbol is 'H', oxygen is 'O', and water is H2O (a compound, not an element with a single symbol).

The Pauli Exclusion Principle states that no two electrons in an atom can have identical sets of four quantum numbers (n, l, ml, ms). This explains electron arrangement in orbitals and the structure of the periodic table. Hund's rule deals with electron pairing in degenerate orbitals. Bohr's model is about electron orbits. Heisenberg's principle is about position-momentum uncertainty.

Element 112 (copernicium, Cn) was officially named in 2009 after Nicolaus Copernicus, the astronomer who proposed the heliocentric model. It was first synthesized in 1996 at the GSI Helmholtz Centre for Heavy Ion Research in Germany. The name honors Copernicus' revolutionary contribution to our understanding of the solar system.

Both As and Sb, belong to groupb15 and are metalloids which have the properties of metals as well as non-metals. Metalloids do not form positive ions in chemical reactions. Metals and poor metals form active positive ions during the chemical reactions.

Atomic spectroscopy is the determination of elemental composition by its electromagnetic or mass spectrum. Atomic spectroscopy is closely related to other forms of spectroscopy.

This option is correct as there are 14 elements in actinoids series, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and Lr

U is the chemical symbol for Uranium, a radioactive element used in nuclear fuel and weapons. Chemical symbols are standardized internationally by IUPAC, with U representing this element on the periodic table.

Yes, the number of shells present in an atom decides the period to which it belongs.

Ni is the chemical symbol for nickel, a transition metal used in coins, stainless steel, and batteries. Nitrogen is N, phosphorus is P, and camphor is an organic compound, not an element.

Rb is the chemical symbol for Rubidium, an alkali metal in group 1. Rhodium is Rh, Radium is Ra, and none of these is incorrect since B is right.

B is the chemical symbol for boron. Barium has the symbol Ba, and bismuth has the symbol Bi. Chemical symbols are either one or two letters and are derived from the element's English or Latin name.

Hydrogen (H) is the most abundant element in the universe, making up about 75% of all normal matter by mass. Helium (He) is second most abundant. Silicon (Si) is common on Earth but not in the universe.

In a neutral atom, the number of electrons equals the number of protons. This balance of positive and negative charges gives the atom its overall neutral charge. If there are 11 protons, there must be 11 electrons for neutrality.