Answer : The correct number of significant figures in scientific notation is
![9.791* 10^2\text{ kilocalorie}](https://img.qammunity.org/2020/formulas/chemistry/middle-school/6tl0d62osw5otvvv0x34mb3w1yymz126bh.png)
Explanation :
The conversion used from kilojoules (kJ) to kilocalories (kcal) is:
1 Joule = 4.184 Calorie
or,
1 kilojoule = 4.184 kilocalorie
As we are given that the energy 234 kJ. Now we have to convert it into kcal.
As,
![1\text{ kilojoule}=4.184\text{ kilocalorie}](https://img.qammunity.org/2020/formulas/chemistry/middle-school/zohfn37jlk0ziwzdxwgydqiwpqh9nso8xj.png)
So,
![234\text{ kilojoule}=\frac{234\text{ kilojoule}}{1\text{ kilojoule}}* 4.184\text{ kilocalorie}=9.791* 10^2\text{ kilocalorie}](https://img.qammunity.org/2020/formulas/chemistry/middle-school/krt5qkl47t8j1hnxq9fwdjy11b0m5v6p8l.png)
Therefore, the correct number of significant figures in scientific notation is
![9.791* 10^2\text{ kilocalorie}](https://img.qammunity.org/2020/formulas/chemistry/middle-school/6tl0d62osw5otvvv0x34mb3w1yymz126bh.png)