Komposisi ion-ion utama dalam air laut secara umum selalu konstan yaitu….

1. 55% Na⁺, 31% Cl^-, 8% K⁺, 4% Mg²⁺, 1% Ca²⁺, and 1% SO42_-
2. 55% Na⁺, 31% Cl^-, 8% Mg²⁺, 4% SO42_-, 1% K⁺, and 1% Ca²⁺
3. 55% Na⁺, 31% Cl^-, 8% Ca²⁺, 4% Mg²⁺, 1% SO42_-, and 1% K⁺
4. 55% Na⁺, 31% Cl^-, 8% SO42_-, 4% Mg²⁺, 1% Ca²⁺, and 1% K⁺
5. 55% Na⁺, 31% Cl^-, 8% SO42_-, 4% K⁺, 1% Mg²⁺, and 1% Ca²⁺