Explanation

Friedrich Wöhler synthesized urea from ammonium cyanate in 1828, marking the birth of organic chemistry.

This experiment disproved the belief that organic compounds could only be made by living organisms.

Explanation

In methane (CH₄), the carbon atom forms four sigma bonds with hydrogen atoms.

To form these four equivalent bonds, carbon undergoes sp³ hybridization, resulting in a tetrahedral structure.

Explanation

The coordination number of a metal atom in a complex is the number of ligands directly attached to it.

In [PtCl(NO)(NH₃)₂], the ligands are:

• Cl⁻ (1)
• NO (1)
• NH₃ (2)

Total number of ligands = 1 + 1 + 2 = 4

The coordination number of Pt is 4, since it is bonded to 4 ligands.

Explanation

Cobalt (Co) is a typical transition metal with partially filled d-orbitals, a key trait of transition elements.

It shows variable oxidation states and forms colored compounds—classic properties of transition metals.

Explanation

Group VB (Group 7 in modern IUPAC numbering) of transition elements includes Manganese (Mn), Technetium (Tc), and Rhenium (Re).

These elements show similar properties and lie vertically in the same group of the periodic table.

Explanation

Elements of Group IVA (Group 14) like carbon (C) and silicon (Si) have very high melting points due to strong covalent bonding.

For example, diamond (carbon) has the highest melting point among all elements.

Explanation

Manganese (Mn) shows a maximum oxidation state of +7, as seen in compounds like KMnO₄ (potassium permanganate).

This is higher than the maximum oxidation states of Cr (+6), P (+5), and S (+6).

Explanation

In the solid and liquid phase, AlCl₃ forms a bridged dimer structure: Al₂Cl₆, where two Al atoms are connected via chlorine bridges.

This happens because Al³⁺ seeks stability through coordinate bonding, leading to a bridge-type (dimeric) structure.

Explanation

When hydrogen loses its electron, it forms H⁺, similar to alkali metals (like Na⁺, K⁺) that also form +1 ions.

Due to this behavior, hydrogen is often placed in Group 1 (alkali metals) in the periodic table.

Explanation

Glycine is the simplest and neutral amino acid, with no extra acidic or basic side chains.

It has a hydrogen atom as its side group (R group), making it electrically neutral at physiological pH.