1.) the actual density of iron is 7.874 g/ml. in a laboratory investigation, jason finds the density of a piece of iron to be 7.921 g/ml.
what is the percent error that is associated with jason's measurement?
a) -4.7 %
b) -0.6%
c) 0.6%
d) 4.7%
2.) rob measures the solubility of three different salts in water at 22celsius
which type of graph should he use to display his data?
a) bar graph
b)line graph
c) histogram
d)scatter plot
only answer if you really know plz.

Answer 1: The percentage error associated with Jason's measurement is 0.6%.

Explanation:

Experimental value of density if iron = 7.921 g/mL

Actual value of density of iron = 7.874 g/mL

Hence, the correct  an option is (C).

Answer 2: The correct answer is bar graph.

Explanation:

In order to express the solubility of three different  salt in water at 22 ° C  graphically Rob must use bar graph. By keeping the solubility on vertical axis and and bars of different salt on horizontal axis with their heights respective their solubility values. Hence, the correct answer is option (A).

As shown in an image attached.

the answer is c.the valence of the atoms combine .