Interpreter
No. Generally, one instruction in a high level language corresponds to many instructions in machine language.
assembler
To add a new machine language instruction to an processor instruction set, you need to replace the microcode of the processor.
A compiler.
It is an assembler language programmer
Assembly langue is translated into machine language by an assembler.
A pseudo-op is an assembly language instruction that specifies an operation of the assembler i.e about the base register & its contents e.g. USING instruction. On the other hand, a machine-op instruction. That represents a machine instruction to the assembler e.g. BR instruction is a machine-op instruction
A machine code program. Machine code is the native language of the machine and the only language actually understood by the machine. However, program instructions can be written using a high-level programming language that the computer can translate into machine code using another machine code program called a compiler.
Assembly language to machine code translation is a "one to one" translation process, as every individual instruction expressed in the assembly language corresponds to exactly one machine instruction. Note this does not hold for pseudo instructions or expanding macros, which are supported by some assemblers.
Interpreater translate the high level language into machine level language line by line
Why would you want to do that? The usual procedure is to translate a high-level language such as Pascal to machine language. If you really want assembly language - perhaps to see how the Pascal compiler does its work - then presumably you can use a disassembler to convert the machine language (the executable file) into assembly language.
Translators are used to translate code in one language to another. There is a need of translators because computers understand machine language so they convert HLL into machine language.