Physical change because it's only changing the shape of the gold.
Answer:

Explanation:
Molecular Formula is representation of the chemical compound in terms of the symbols of all the elements that are present in the compound followed by subscripts, which give the count of each element in that compound.
We need to write the molecular formula of Tricarbon nonachloride. Tri means three, so Tricarbon means there are 3 atoms of Carbon. Likewise, nona stands for 9, so nonachloride means there are 9 atoms of chlorine. Therefore, we can represent nonachloride as:
Carbon (3 atoms) Chlorine (9 atoms) = 
Thus, molecular formula of Tricarbon nonachloride is 
Answer:
K2CrO4
Explanation:
To find the empirical formula, we need to divide each element by its atomic mass. The atomic masses of potassium, chromium and oxygen are 39.0983, 51.9961 and 15.999 respectively. We make the divisions as follows:
K = 1.04/39.0983 = 0.027
Cr = 0.70/51.9961 = 0.013
O = 0.86/15.999 = 0.054
We now divide by the smallest which is the number of moles of the Chromium
K = 0.027/0.013 = 2
Cr = 0.013/0.013 = 1
K = 0.054/0.013 = 4 approximately
The empirical formula is thus:
K2CrO4
Make sure that you understand what they are asking you from this question, as it can be confusing, but the solution is quite simple. They are stating that they want you to calculate the final concentration of 6.0M HCl once a dilution has been made from 2.0 mL to 500.0 mL. They have given us three values, the initial concentration, initial volume and the final volume. So, we are able to employ the following equation:
C1V1 = C2V2
(6.0M)(2.0mL) = C2(500.0mL)
Therefore, the final concentration, C2 = 0.024M.
Answer:
Should be number 4, quartz.
Explanation:
Quartz is rougher than calcite, therefore it's able to scratch it.