The distance between the sun and earth is about 1.5X10^11 m. express this distance with an SI prefix and kilometers

First, we write the SI prefixed. The SI unit for distance is meters.

Kilo = 10³

Mega = 10⁶

Giga = 10⁹

Terra = 10¹²

Because our value has ten to the power of 11, we will use the closest and lowest power prefix, which is giga.

1.5 x 10¹¹ / 10⁹

= 1.5 x 10² Gm or 150 Gm

Writing in kilometers, we simply repeat the procedure except we divide by 10³ this time.

1.5 x 10¹¹ / 10³

= 1.5 x 10⁸ km