Which of the following reactions is a combination reaction? MCQ with Answer and Explanation

Explanation:
Stainless steel is an alloy of iron with chromium (minimum 10.5%), often nickel, and sometimes molybdenum. Chromium forms a passive oxide layer (Cr₂O₃) that prevents rusting. Brass is Cu + Zn. Bronze is Cu + Sn. Solder is Pb + Sn. Stainless steel is used in kitchen utensils, surgical instruments, and architecture. The most common type is 304 stainless (18% Cr, 8% Ni).

Explanation:
The Tyndall effect is the scattering of a beam of light by a medium containing small suspended particles (like colloids). The particle size must be comparable to or smaller than the wavelength of light. True solutions do not show this effect because their particles are too small to scatter light effectively.

Explanation:
One carbon atom with four hydrogens is methane (CH₄). Ethane is C₂H₆, propane C₃H₈. Methanol is CH₃OH (alcohol). Methane is the simplest alkane.