Answer:
Which statements describe how chemical formulas, such as H2O, represent compounds? ... They show the elements that make up a compound. They show the types of atoms that make up a molecule. They show the number of each type of atom in a molecule.
The density of a material is the mass of the material per unit volume. Here the weight of the same metal is 44.40g, 40.58g and 38.35g having volume 4.8 mL, 4.7 mL and 4.2 mL respectively. Thus the density of the metal as per the given data are, 
= 9.25g/mL, 
= 8.634g/mL and 
= 9.130g/mL respectively.
The equation of the standard deviation is √{∑(x - 
)÷N}
Now the mean of the density is {(9.25 + 8.634 + 9.130)/3} = 9.004 g/mL.
The difference of the density of the 1st metal sample (9.25-9.004) = 0.246 g/mL. Squaring the value = 0.060.
The difference of the density of the 2nd metal sample (9.004-8.634) =0.37 g/mL. Squaring the value = 0.136.
The difference of the density of the 3rd metal sample (9.130-9.004) = 0.126 g/mL. Squaring the value 0.015.
The total value of the squared digits = (0.060 + 0.136 + 0.015) = 0.211. By dividing the digit by 3 we get, 0.070. The standard deviation will be 
. Thus the standard deviation of the density value is 0.265g/mL.
Answer:
What procedure did you use to complete the lab?
→Procedures that needs to be considered to complete the lab are- a thorough knowledge of lab assignments, knowledge about safety equipment, reviewing the MSDS of chemicals for lab experiment etc.
<h3>Explanation:</h3>
To be lab prepared one must follow these procedures-
1. One should have the knowledge of lab assignments to make the lab experiment easier.
2. To be aware about safety equipment and their uses in lab, like- the location of fire extinguisher in lab.
3. To know the steps of experiments to be performed
4. To fill notebook of lab with information regarding the experiment
5. One should review the data sheets of chemicals material safety.
6. To put on all the necessary dressings to perform experiment.
7. To have complete understanding about the experiment disposals.
Answer:
<u>mnemonic</u><u> </u><u>isjdndbeudxhdnrhcurhrfkrr</u>
A concave<span> surface, </span>structure<span>, or line. tr.v. con·caved, concaving, con·caves.
hope that helped</span>
