The composition is:
- sodium: 1 %
- magnesium: 0,13 %
- potassium: 0,04 %
- calcium: 0,04 %
- chloride: 1,94 %
- sulfur: 0,09 %
It is a branch of chemistry which studying chemical processes and chemical composition of ocean waters.
from minerals in rivers and lakes running into the ocean
The chemical composition of water remain unchanged.
The chemical composition remain unchanged.
It is a chemical change (reaction) because the chemical composition of the products (O2 and H2) is different from the chemical composition of the water (H2O).
Regarding the composition of ocean water, I would describe it as a homogeneous mixture, or solution.
The chemical composition of water remain constant.
The chemical composition of water is H2O.
The chemical composition of a solution made by dissolving NaCl in water is sodium chloride (NaCl) and water (H2O).
Mixing water with clay is not a chemical change, as no new substances are formed. It is a physical change, where the clay particles are dispersed in the water but retain their original chemical composition.
Boiling water is a physical change because it does not change the chemical composition of the water.
When ice melts, the chemical composition remains the same. Ice is just the solid state of water, so when it melts, it turns into liquid water. The molecules in ice rearrange themselves into a more disordered state to become liquid water, but the chemical makeup of the water molecules themselves does not change.