Answer
$M=K$
Work Step by Step
16.99% of one mole of the compound weighs $16.00g$. This means the whole compound weighs $16.00\times\frac{100}{16.99}=94.17$. Subtracting the weight of O from the total weight gives us the molar mass of the unknown metal multiplied by 2. $94.17-16.00=78.17g$. Divide this by 2 to get the molar mass of the metal. $78.17g\div2=39.09\frac{g}{mol}$ Looking at the periodic table we see that the unknown metal is $K$.
