The synthetic element immediately after mendelevium is nobelium.
Mendelevium is element 101, with the symbol Md, and nobelium is element 102, with the symbol No. Both belong to the actinide series, the row of heavy elements placed beneath the main body of the periodic table. The sequence is determined by increasing atomic number, so nobelium follows mendelevium directly.
Mendelevium was first produced in 1955 by bombarding einsteinium with alpha particles. It was named for Dmitri Mendeleev, whose periodic law inspired the modern periodic table. Nobelium was named for Alfred Nobel and was eventually credited to researchers at the Joint Institute for Nuclear Research after earlier discovery claims were disputed.
A common mix-up is with lawrencium, element 103, which follows nobelium rather than mendelevium. Curium is element 96, while fermium is element 100, so both come earlier in the actinide series.