We are learning about the Crystalline state and its models. The question says Use diameters of 17, 19, 21, and 24 nm for a dime, penny, nickel, and quarter, respectively, to calculate r+/r– for the...

asked by @valentinac9 • about 2 years ago • Chemistry • 5 pts

various “coin ion” combinations, assuming the dime to be the cation. With actual coins, determine the number of anions that can touch the dime with each combination. I really don't know where to start

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1 answer

Hey there. Interesting question. In this question we need to determine how many coins (pennies, quarter, and nickels) you can put around the circumference of a dime. So we have diameters given and so recall the radius is the diameter divided by 2.

The radius of a dime would be 17/2 = 8.5 nm. We are told this is the cation so it's r+ The radius of a penny would be 19/2 = 9.5 nm. Make this r- penny The radius of a nickel would be 21/2 = 10.5 nm. Make this r- nickel. The radius of a quarter would be 24/2 = 12.0 nm. Make this r- quarter.

So now divide r+ by the r- of each coin to determine the different combinations.

dime/penny = r+/r- = 8.5/9.5 = 0.895 dime/nickel = r+/r- = 8.5/10.5 = 0.810 dime/quarter = r+/r- = 8.5/12.0 = 0.708

This gives us

No. of penny anions that can touch dime cation = 6

No. of nickel anions that can touch dime cation = 5

No. of quarter anions that can touch dime cation = 5

answered by @jules • about 2 years ago