Indentured servants came to the colonies .

in 1607

Explanation:

Indentured servants first arrived in America in the decade following the settlement of Jamestown by the Virginia Company in 1607.

In pure water, the concentration of hydronium ions, or H⁺, will equal the concentration of hydroxide ions. That is [H⁺] = [OH⁻].

Remember that Kw = [H⁺][OH⁻] for water and if [H⁺] and [OH⁻] are both equal, we can easily solve for them by taking the square root of Kw.

[H⁺] = [OH⁻] = sqrt(1.47*10^-14) = 1.21*10^-7

The concentration of hydroxide ions at 30 degrees Celsius is 1.21*10^-7