nitrogen
None, but lead-acid accumulators contain sulphuric
The first IBM 702 had two 512 character accumulators.
Accumulators, or energy storage devices, typically store either electrical energy in the form of chemical energy (such as in batteries) or potential energy (such as in hydraulic accumulators). The stored energy can be released when needed to power various systems or devices.
Accumulators.
store energy
pressurized
Photovoltaic arrays are used( in conjunction with accumulators - batteries - to store energy when the satellite's solar panels are in shadow).
Most hydraulic systems do not have accumulators.
yes
Lead acid accumulators
Assuming 2 was already in one accumulator and 2 was already in another accumulator and the two accumulators were wired together for addition, 200 microseconds (one addition cycle). The values don't matter, any numbers that fit in the 10 digit accumulators can be added in that time. If the numbers are not already in those accumulators more cycles (and wiring) will be needed to get them there.