Answer:
[tex]\boxed {\boxed {\sf 2.8 \ g/mL}}[/tex]
Explanation:
Density is an object's mass per unit volume. The formula for calculating density is:
[tex]\rho= \frac{m}{v}[/tex]
The mass of the object is 5.8 grams and the volume is 2.1 milliliters.
Substitute the variables into the formula.
[tex]\rho = \frac{5.8 \ g}{2.1 \ mL}[/tex]
Divide.
[tex]\rho = 2.761904762 \ g/mL[/tex]
The original values of mass and volume (5.8 and 2.1) have 2 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. The 6 in the hundredth place tells us to round the 7 in the tenth place up to an 8.
[tex]\rho \approx 2.8 \ g/mL[/tex]
The density of the object is approximately 2.8 grams per milliliter.
