Which value on the soil pH scale is considered neutral?

Which value on the soil pH scale is considered neutral?

• A. 7
• B. 6.5
• C. 7.5
• D. 8.0

Answer: (A)

The main idea is that neutrality on the pH scale is seven. This means there are equal amounts of hydrogen ions and hydroxide ions in the solution. Values below seven indicate acidity (more hydrogen ions), while values above seven indicate basic or alkaline conditions (more hydroxide ions). Because pH is a logarithmic scale, each step represents about a tenfold change in hydrogen ion concentration, so shifting from neutral to slightly acidic or slightly alkaline can noticeably affect nutrient availability in soil. Among common options, seven is neutral, while 6.5 is mildly acidic, 7.5 is mildly alkaline, and 8.0 is more alkaline.

The main idea is that neutrality on the pH scale is seven. This means there are equal amounts of hydrogen ions and hydroxide ions in the solution. Values below seven indicate acidity (more hydrogen ions), while values above seven indicate basic or alkaline conditions (more hydroxide ions). Because pH is a logarithmic scale, each step represents about a tenfold change in hydrogen ion concentration, so shifting from neutral to slightly acidic or slightly alkaline can noticeably affect nutrient availability in soil. Among common options, seven is neutral, while 6.5 is mildly acidic, 7.5 is mildly alkaline, and 8.0 is more alkaline.