Write the Mass of Mars, Which Is Approximately 642,000,000,000,000,000,000,000 Kg $6.42 \times 10 ^ { 20 }$

Multiple Choice

Write the mass of Mars, which is approximately 642,000,000,000,000,000,000,000 kg, in scientific notation.

A) $6.42 \times 10 ^ { 20 }$
B) $6.42 \times 10 ^ { 24 }$
C) $6.42 \times 10 ^ { 22 }$
D) $6.42 \times 10 ^ { 23 }$
E) $6.42 \times 10 ^ { 21 }$