Explanation

2H₂ + O₂ → 2H₂O

This balanced equation ensures 4 hydrogen atoms and 2 oxygen atoms on both sides.

It correctly represents the formation of water from hydrogen and oxygen gases.

Explanation

Ammonia (NH₃) has a trigonal pyramidal shape due to one lone pair on the nitrogen atom.

The molecular geometry results from sp³ hybridization and lone pair-bond pair repulsion.

Explanation

Sodium is a reducing agent because it loses electrons easily.

Oxidizing agents gain electrons; chlorine, nitric acid, and nitrogen can act as oxidizers, but sodium cannot.

Explanation

The given compound is an ionic compound

It is made up of:

• one potassium
• one manganese,
• four oxygen atoms.

Oxidation numbers of potassium (K) and oxygen (O) are +1 and -2 respectively.

Let us assume that the oxidation number of Mn is $x$.

Since ionic compounds are neutral, the net charge on them is zero.

(Oxidation number of K) + (Oxidation number of Mn) + (4 $\times$ The oxidation number of O) = $0$

(1)$\times$(K) + (1)$\times$(Mn) + 4$\times$(O) = $0$

$(1)$$\times$(+1) + (1)$\times$($x$) + 4$\times$(-2) = $0$

$x$ = +7

Hence, the oxidation number of $\text{Mn}$ in ${\text{KMnO}}_4$ is +7.

Explanation

Sodium is a metal, and metallic bonding involves positive ions in a lattice surrounded by a sea of free (delocalized) electrons.

This structure gives metals properties like electrical conductivity and malleability.

Explanation

The Arrhenius theory (1887) defines:

Acids: Substances that dissociate in water to produce H⁺ ions (protons), such as:

HCl → H⁺ + Cl⁻

Bases: Substances that dissociate in water to produce OH⁻ ions (hydroxide ions), such as:

NaOH → Na⁺ + OH⁻

Explanation

Ionization energy is the minimum energy needed to remove one electron from a gaseous atom in its ground state.

It reflects how tightly an electron is held — higher ionization energy means stronger attraction to the nucleus.

Explanation

Liquids that evaporate quickly are called volatile liquids. 

Volatility refers to the tendency of a liquid to vaporize or evaporate quickly, often at room temperature or below. 

Examples of volatile liquids include:

• Alcohol (e.g., ethanol, isopropanol)
• Acetone
• Gasoline
• Perfumes
• Essential oils

Explanation

Chemical equilibrium occurs when the forward and reverse reactions occur at the same rate.

At this point, the concentrations of reactants and products remain constant, not necessarily equal.

Explanation

NH₄Cl (Ammonium chloride) contains three types of chemical bonds:

• Covalent bond → Between N (Nitrogen) and H (Hydrogen) in the NH₄⁺ (Ammonium ion).
• Coordinate (Dative) bond → Between N and one of the H atoms, where nitrogen donates a lone pair.
• Ionic bond → Between NH₄⁺ (Ammonium ion) and Cl⁻ (Chloride ion).