In a lead-acid battery, the electrolyte is: MCQ with Answer and Explanation

Explanation:
Salt (NaCl) dissolved in water increases the electrical conductivity of the electrolyte, facilitating the electrochemical corrosion process. This is why iron rusts faster in coastal areas and on roads treated with deicing salts. Dry air prevents rusting (needs moisture). Coating with paint blocks oxygen and moisture. Vacuum has no oxygen.

Explanation:
15/5 = 3 half-lives. Remaining = (1/2)³ = 1/8 = 12.5%. Each half-life reduces the amount by half.

Explanation:
Isotopes are atoms of the same element (same atomic number, same number of protons) but different mass numbers due to varying number of neutrons. For example, ¹²C, ¹³C, ¹⁴C. Their chemical properties are similar but physical properties (mass, density, rate of diffusion) differ. Isobars have same mass number but different atomic numbers.