Step 1: Understanding the Concept:
Mass and energy are interconvertible according to Einstein's mass-energy equivalence relation.
Step 2: Calculation:
Formula: $E = mc^2$
Given: $m = 1.0\text{ kg}$, $c = 3 \times 10^8\text{ m/s}$.
$$E = 1.0 \times (3 \times 10^8)^2$$
$$E = 1.0 \times 9 \times 10^{16}$$
$$E = 9 \times 10^{16}\text{ J}$$
Step 3: Final Answer:
The energy equivalent is $9 \times 10^{16}$ J.