Which of the following is an alpha particle? MCQ with Answer and Explanation

Explanation:
Natural soap molecules have straight-chain fatty acid salts that are easily broken down by microorganisms through β-oxidation. This makes them biodegradable. Some synthetic detergents with branched chains are non-biodegradable and cause pollution. Linearity allows enzymes to act. Aromatic and fluorinated compounds resist biodegradation.

Explanation:
Diamond is the hardest known natural material due to its rigid three-dimensional network of covalent bonds with sp³ hybridization, forming a tetrahedral structure. Graphite is soft and slippery because of its layered structure with weak van der Waals forces between layers. Coal is an amorphous form of carbon. Diamond is used in cutting, drilling, and jewelry. Mohs hardness of diamond is 10.

Explanation:
Across a period, the number of electron shells remains the same, but the nuclear charge (protons) increases. The added electrons enter the same valence shell, so the effective nuclear attraction on the electrons increases, pulling them closer and shrinking the atomic radius. Down a group, radius increases due to addition of shells. Electron-electron repulsion alone does not account for the trend. Atomic mass generally increases across a period.