During hydrolysis, must be added before the bonds can be broken. (look at flash animation on hydrolysis)

The correct answer is water.

During hydrolysis, water must be added before the bonds can be broken.

For example, sucrose undergoes hydrolysis to break into glucose and fructose. Here sucrose is a disaccharide and glucose and fructose are monosaccharides.  

Sucrose + H₂O → glucose + fructose

Esters are formed by the combination of carboxylic acid and alcohol.

But the hydrolysis of ester causes the release of carboxylic acid and alcohol.

RCOOR'(ester) + H₂O → RCOOH(carboxylic acid) + R'OH(alcohol)

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally