Basic Math/General Chemistry Problem

[skyisblue]

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Okay, I've done this problem twice with and without a calculator, but my answers always come up to be the same yet different from the solution guide. Here's the problem:

(a) How many electrons are required to give a total mass of 1.0 ug (micrograms)? (b) What is the mass of the same number of neutrons?

One should know that the mass of an Electron is 9.1094 x 10 to the Minus 31 kilograms and that the mass of a Neutron is 1.6749 x 10 to the Minus 27 kilograms.

Help guys!

 

[Streetwolf]

a) I get 1.0978 x 10^21.
b) With that number I get 1.8387 mg.

 

[skyisblue]

a) I get 1.0978 x 10^21.
b) With that number I get 1.8387 mg.

We came up with the same answer! I think the solution guide is wrong, which says that the answer is 1.1 x 10 to the 24th and 1.8g respectively.

 

[Streetwolf]

Those answers correspond to a total mass of 1.0 mg.

The neutron is approximately 1800 times the mass of an electron. So if you had the same # of neutrons and electrons, the mass of the neutrons would be 1800 times as great.

Part (b) you are under that assumption, so if the mass of the electrons is 1 ug, then the mass of the neutrons is 1800 ug = 1.8 mg. The answer guide is obviously wrong. If the question said the electrons were 1.0 mg, then the neutrons would be 1800 mg = 1.8 g.

 

[skyisblue]

Those answers correspond to a total mass of 1.0 mg.

The neutron is approximately 1800 times the mass of an electron. So if you had the same # of neutrons and electrons, the mass of the neutrons would be 1800 times as great.

Part (b) you are under that assumption, so if the mass of the electrons is 1 ug, then the mass of the neutrons is 1800 ug = 1.8 mg. The answer guide is obviously wrong. If the question said the electrons were 1.0 mg, then the neutrons would be 1800 mg = 1.8 g.

You are the man Streetwolf, I'm assuming man or you could be a woman. Either one thumbs up!👍