Answer :
To find out how many kilograms of calcium are present in a 195-pound man, given that 1.4% of the mass of a human body is calcium, we can follow these steps:
Convert Pounds to Kilograms
First, we need to convert the weight from pounds to kilograms because the final answer should be in kilograms.
The conversion factor from pounds to kilograms is:
[tex]1 \, \text{pound} = 0.453592 \, \text{kilograms}[/tex]
Therefore, a 195-pound man weighs:
[tex]195 \, \text{pounds} \times 0.453592 \, \text{kg/pound} = 88.45044 \, \text{kg}[/tex]
Calculate the Mass of Calcium
We know that 1.4% of the body mass is calcium. Thus, we can calculate the mass of calcium by multiplying the total body mass in kilograms by 1.4% (or 0.014 when expressed as a decimal).
[tex]\text{Mass of calcium} = 88.45044 \, \text{kg} \times 0.014 = 1.23830616 \, \text{kg}[/tex]
Rounding this to two significant figures, we find that the mass of calcium is approximately 1.2 kg.
Therefore, the correct answer is option 3: 1.2 kg Ca.
