Regardless of the nutrients present in the soil, if the pH is not suitable plants cannot grow. Soils can be basic or acidic and usually measures between a pH of 4 and 10 on the pH scale. What pH level is best for most plant growth?

A) Most plants grow best in soils with a pH of between 4 and 5.

B) Most plants grow best in soils with a pH of between 5 and 7.

C) Most plants grow best in soils with a pH of between 4 and 10.

D) Most plants grow best in soils with a pH of between 7 and 10.

1. seamount a raised footwall block between normal fault creates this 2. syncline break between rocks where a hanging wall rises relative to a footwall 3. hot spring on rolling hills, this a dip between hills 4. volcanic neck created when a block with hanging walls slips down between normal faults 5. caldera underwater volcano that never reaches above sea level 6. horst natural hot water on earth's surface containing many minerals 7. graben underwater volcano whose top is eroded flat by waves 8. crater less than a mile in diameter; looks like a bowl at the top of a volcano 9. guyot magma that filled the central vent that remains after the volcano has eroded 10. reverse fault over 1 mile in diameter; looks like a bowl over a volcano