In the video, the water level was 15 milliliters before adding the chain, and 20 milliliters after adding the chain. When I weighed the chain, its mass was 66.7 grams.

I believe the chain is solid metal (not gold plated), but is probably a blend of gold and other metals. I looked up that gold has a density of 19.3 g/ml, while the other metals like silver and copper usually blended with gold have a combined density of about 9.7 g/ml.

Determine what percentage of the chain is gold, by mass, to at least 1 decimal place?

Whats the procedure?

Explanation:

1. First find the density of your chain

                      = Volume of Final level of water - initial level of water

                     = 20 ml - 15 ml = 5 ml

2. Second, write the denisty of the chain as the weighted average of the densities of the other metals:

Mass of gold × density of gold + mass of other metals × density of other metals, all divided by the mass of the chain.

Calling x the amount of gold, then the amount of other metals is 66.7 - x:

Then, there are 26.47 grams of gold in 66.7 grams of chain, which yields a percentage of: