Which of the following is an alkali metal?

By which method can the concentration of alkali metals be determined?

Which one of the following alkali metals gives hydrated salts?

The correct statement$(s)$ among $I$ to $III$ with respect to potassium ions that are abundant within the cell fluids is/are :
$I.$ They activate many enzymes
$II.$ They participate in the oxidation of glucose to produce $ATP$
$III.$ Along with sodium ions,they are responsible for the transmission of nerve signals

Which of the following is an ore of potassium?

Zeolite is a silicate of two metal ions $X$ and $Y$. $X$ and $Y$ are respectively