1. **State the problem:** We are asked to find: a) The planet with the greatest mass. c) The difference between the masses of Jupiter and Saturn, expressed in standard form. 2. **Identify the masses from the table:** - Mercury: $3.3 \times 10^{23}$ kg - Jupiter: $1.898 \times 10^{27}$ kg - Earth: $5.97 \times 10^{24}$ kg - Mars: $6.42 \times 10^{23}$ kg - Saturn: $5.68 \times 10^{26}$ kg 3. **Answer part (a):** The greatest mass is the largest number among these. Clearly, $1.898 \times 10^{27}$ (Jupiter) is the largest. **Answer:** Jupiter 4. **Answer part (c):** We need to find the difference: $$\text{Difference} = \text{Mass of Jupiter} - \text{Mass of Saturn}$$ $$= 1.898 \times 10^{27} - 5.68 \times 10^{26}$$ 5. **Calculate the difference:** Rewrite $5.68 \times 10^{26}$ as $0.568 \times 10^{27}$ to have the same power of 10: $$1.898 \times 10^{27} - 0.568 \times 10^{27} = (1.898 - 0.568) \times 10^{27} = 1.33 \times 10^{27}$$ 6. **Final answer for (c):** $$1.33 \times 10^{27}$$ kg Thus, the difference in mass between Jupiter and Saturn is $1.33 \times 10^{27}$ kg.