$a)5000=5\cdot 1000=5\cdot {10}^3$

$b)78000=7,8\cdot 10000=7,8\cdot {10}^4$

$c)108000=1,08\cdot 100000=1,08\cdot {10}^5$

$d)3250000000=3,25\cdot 100000000=3,25\cdot {10}^9$

$e)0,00008=8\cdot 0,00001=8\cdot {10}^{-5}$

$f)0,000515=5,15\cdot 0,0001=5,15\cdot {10}^{-4}$

$g)0,00000308=3,08\cdot 0,000001=3,08\cdot {10}^{-6}$

$h)0,0000000002001=2,001\cdot 0,000000001=2,001\cdot {10}^{-10}$