What is size of data bus and the address bus in 8085?

A 16-bit uP operates on instructions and data in 16-bit quantities. Therefore the databus is 16-bits. A 16-bit uP may also operate on larger quantities of data, however multiple CPU registers must be concatenated in order to maintain the data element in the uP register space. The data is always delivered to the processor 16 bits at a time. The amount of memory which it can address is a separate issue---the address bus size is totally distinct from the data bus size. The data bus determines how much memory may be delivered to the uP per cycle. The address bus size determines how much physical memory may actually be accessed by the uP. Therefore it is variable depending on how much memory is available. Typical systems today have 32-bit address busses which limit addressable memory to 4Gigabytes. (2^32) = 4G.