What happens when heavy exercise results in too much acid in the human body? Excess H+ is absorbed by bicarbonate ions. Bicarbonate releases one H+ to become carbonate.
H2CO3 is formed from H2O and CO2.
Bicarbonate is formed from carbonate.

It’s A, Excess H+ is absorbed by bicarbonate ions.

From negative to negative

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.