What 2 ions are most common in both blood plasma & interstitial fluid?

We know that when substance donate the electron then it from positive charge but when substance take electron then it form negative charge.

The most common ions in blood plasma

1. Cation - Sodium (Na+)

2. Anion - Chloride (Cl-)

The most common ions interstitial fluid

1. Cation - Potassium

2. Anion - Chloride