Answer:
[tex]\large\boxed{\large\boxed{7.9\times 10^9g}}[/tex]
Explanation:
The information of the content of the element strontium in seawater is incomplete. The complete information is:
1. First, convert the given volume of seawater given to kilograms
[tex]9.84\times 10^{8} m^3\times \dfrac{1,000dm^3}{m^3}\times \dfrac{1,000cm^3}{dm^3}\times 1.0\dfrac{g}{cm^3}\times\dfrac{1kg}{1,000g}=9.84\times 10^{11}kg[/tex]
2. Second, multiply the given concentration of the element strontium by the amount of seawater in kilograms
[tex]8.0\times 10^-1cg/kg\times 9.84\times 10^{11}kg\times 1g/100cg=7.872\times 10^9g[/tex]
3. Finally, round to two significant figures:
[tex]7.9\times 10^9g[/tex]