A nurse is reviewing the client's serum electrolyte levels which are as follows: Sodium: 138 mEq/L (138 mmol/L) Potassium 3.2 mEq/L (3.2 mmol/L) Calcium 100 mg/dL (2.5 mmol/L) Magnesium 20 mEq/L (1.0 mmol/L) Chloride 100 mEq/L (100 mmol/L) Phosphate 4.5 mg/dL (26 mEq/L) Based on these levels, the nurse would identify which imbalance?