Will ddr2 nvidiageforce 9500gt graphics card work in ddr3 motherboard

look at the requirements for the video card. does your system meet those? notmally they require a pcie-slot, if its a pcie card, a particular level of PSU is required, ram/cpu etc. Just look at the box or manufacturers web site for compatability details. DD2/DDR3 has nothing to do with it, it goes in a pcie slot not a ram slot.