Which Ion Is Not Found in Sea Water in a Concentration

question 36

Multiple Choice

Which ion is not found in sea water in a concentration high enough to be an industrial source of the metal?

• A) Ca²⁺
• B) Mg²⁺
• C) Na⁺
• D) K⁺
• E) Ag⁺

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Definitions:

Retentive

Memory or functions in a control system that retain their value or state even after the system is powered down or rebooted.

Nonretentive

In PLC programming, a term referring to memory or data that is not retained after power loss.

Retentive Timer Reset

A function in PLC programming that allows a timer to retain its accumulated value even after a reset condition has been removed or power to the PLC has been cycled.

Timer Resets

The process of returning a timer to its initial state or set value in control systems or programming.