Answer
(a) $7.0 \times 10^{-5}$ m;
(b) $2.0 \times 10^{10}$ kg;
Work Step by Step
(a) As we can see in the previous table: $μ$ = $10^{-6}$; therefore:
$70$ $μm$ = $70 \times 10^{-6}$ $m$ = $7.0 \times 10^{-5}$ $m$
(b) T equals $10^{12}$; therefore:
$20$ $Tg$ $=$ $20 \times 10^{12}$ $g$ = $2.0 \times 10^{13}$ $g$
But, the SI unit for mass is actually kg, and $kg= 10^3 g$; therefore:
$2.0 \times 10^{13}$ $g = 2.0 \times \frac{10^{13}}{10^3} kg = 2.0 \times 10^{10}$ $kg$.