An atom (or aggregation of atoms) of a particular element identified by mass number and distinguished by the number of neutrons in its nucleus.

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Mass Spectrum and Molecular Ion peaks

If a molecule contains four chlorine atoms, how many molecular ion peaks will this compound show in its mass spectrum?
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Placing the atomic mass and number of an element… [closed]

Why are the atomic and the mass numbers of an element flipped in the textbooks relative to the periodic table?
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1answer
2k views

Does hydrogen really have seven isotopes?

I know that there are 3 isotopes of Hydrogen. But according to this website it is showing 7 http://periodictable.com/Properties/A/KnownIsotopes.htmlWebsite
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1answer
165 views

On the stability of deuterium

The isotope of hydrogen, tritium, is indeed radioactive resulting in He 3 through beta decay. But what of the radioactively 'stable' isotope deuterium? Are all deuterium atoms destined to be ...
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2answers
90 views

Would C bond with H or D?

Is a C-D bond better than C-H bond? I mean if carbon has a chance to either for a bond with deuterium or hydrogen what would it choose and why? What if tritium competes too?
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2answers
408 views

Where does the molar mass difference between N₂ and CO come from?

The molar masses of $\ce{N2}$ is 28.0134 g/mol, for $\ce{CO}$ it's 28.0101 g/mol (WolframAlpha computation). Of course, they do have the same mass in atomic units (28). My question is, where does ...
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1answer
130 views

Is there a simple way to separate deuterium oxide from tap water?

I understand that tap water contains minute amounts of deuterium oxide (heavy water). Is there a simple way to separate, concentrate the $\ce{D2O}$?
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231 views

Are radioactive isotopes of silver dangerous?

I know we all think of things like uranium as being radioactive in the nasty radiation poisoning sort of way. But do elements like silver have similar effects in their radioactive isotopes? I'm an ...
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2answers
48 views

Can carbon dating tell how long a species would survive?

Carbon ($\ce{^{14}C}$) is used to determine how long a particular species has lived or how old it is. Can we use the same isotope to derive how long a species may survive? (My understanding is still ...
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568 views

Biological Consequences of Asteroid Mining—Death by Isotope?

It's been documented that NASA hope to capture an asteroid in 2025, and have subsequent aims to mine that asteroid. If if this is successful, we would expect other asteroids to be mined in the future. ...
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1answer
101 views

Questions about combustion and isotopic abundance

the combustion of 0.214g of sulfur provided exactly 0.428g of sulfur dioxide. After a second try, 0.782g of SO2 was obtained. What mass of sulfur was used? The combustion of lithium forms lithium ...
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2answers
3k views

The formula for finding the percentage of isotopes in an element's atomic weight?

In my class my teacher showed us how to find it, with a method, but he didn't really state the formula. I conjured up a formula from what I observed and it works. Here it is: $$ \frac{i_1x + ...
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1answer
88 views

Protactinium-234 half-life

This is going to seem like a rather daft question, but what is the definitive half-live for protactinium-234 (234Pa)? I'm seeing lots of different answers in various academic papers etc. For ...
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2answers
371 views

Is real water made up of heavy water and light water?

I need to know, is real water made up of heavy water which is formed with deuterium, and light water which is water by protium? We know that hydrogen has three major isotopes, including protium and ...
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1answer
86 views

Can I perform a stable isotope analysis at home?

I'm interested in measuring the stable isotope ratios of some bird feathers. I'm aware that a mass spectrometer is required to measure stable isotope ratios. Is it possible to measure stable isotope ...
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1answer
29 views

What does $\mathrm{A}_r(\mathrm{H})$ represent when calculating the average natural weight of an elemental atom?

I have a question that explains the weights and abundances of various hydrogen isotopes, and the question concludes by asking to: Calculate the atomic mass of hydrogen $\mathrm{A}_r(\mathrm{H})$ ...
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4answers
426 views

Chemical properties of isotopes

I've always heard that different isotopes of the same element have exactly the same chemical properties. But for example, I've read that some compounds which have hydrogen atoms interchanged by ...
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1answer
563 views

What is deuterium-depleted water actually used for?

I noted, flipping through the paperback Alfa Aesar catalogue today, that they sell deuterium-depleted water. Under the usage category, they list 'NMR'. I'm trying to work out what specific use this ...
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4answers
391 views

Is there a simple field test for heavy water?

Thought experiment Given two glasses of water, how would one detect which glass contains heavy water, and which contains potable water without using complicated laboratory equipment? Something like ...