A x1 PCIe card can be detected in pcie x16 slot?

Hi, I'm new to TekSyndicate Does anyone know of any adapters that can convert a single x16 slot into 4 x4 slots? I've searched around but

PCIe x16 slot with faster bandwidth and lower impedance 2 PCIe Slot PCIe x4 slot with Lower impedance can maintain its performance

can i use gen 4 nvme in gen 3 slot In the central area between the CPU socket and the PCI-E x16 slot, we can see additional redrawers for distributing and amplifying PCI-E

candy pop 2 slot You'll be able to do more with less in this case, since a PCIe x8 slot can handle almost exactly what a PCIe x16 slot can currently