Questions tagged [elements]

A pure chemical substance consisting of a unique type of atom with a distinguished by its atomic mass.

Filter by
Sorted by
Tagged with
-1
votes
1answer
579 views

It is possible to create any metal? [duplicate]

This question just popped up in head. There are many things which we are good at. We are good at: constructions. build stuff. destroying things. repairing things. cleaning. But I want also to know, ...
3
votes
1answer
220 views

Extracting sulphur from hot springs with medieval technology?

For the sake of a dungeons and dragons game. Could sulphur be deposited on/extracted from hot springs water through evaporation or other proess?
8
votes
2answers
1k views

Can we recycle garbage with the principles of mass spectrometry?

'Mass Spectrometry (MS) is an analytical technique that sorts ions based on their mass (or "weight"). Mass spectrometry is used for many chemical analyses, ranging from the analysis of a complex ...
11
votes
3answers
12k views

What is dust made of?

I was cleaning my blinds today, and wanted to know what the primary components of dust are. I know that it is made of microorganisms and other particles, but I do not want to guess that it will be $\...
3
votes
4answers
212 views

Does it change the compound if the element letters in its molecular formula are switched?

Does it change the compound if the element letters are switched? ex. $\ce{HO}$ or $\ce{OH}$. Are those two different compounds or are they one in the same?
16
votes
4answers
23k views

Why is fluorine more reactive than chlorine?

Why is fluorine more reactive than chlorine despite chlorine having a higher electron affinity?
1
vote
1answer
159 views

What is the chemical composition of the human body? [closed]

What is the average percent composition of each element in the average human body?
3
votes
1answer
3k views

Does pyrite retain the magnetic properties of its element iron?

You are walking in the mountains and pick up what looks like a nugget of gold. You're aware that fools gold (iron pyrite, $\ce{FeS2}$) exists. Create an experiment to test if this is pure gold or iron ...
3
votes
2answers
99 views

Atomic weight = expected weight?

The atomic weight of an element, is it accurate to say that another way to think of it is the expected value of that element's weight if we were to sample one at random from the environment? Are man-...
3
votes
1answer
2k views

Why is silicon used in computer chips?

Most computer chips contain or are made of silicon. Why silicon? Why not copper or tellurium or some such?
5
votes
2answers
4k views

Why do all atomic masses have decimals if there are some elements that don't have isotopes?

I understand that the way to calculate the atomic mass is to obtain a weighted average of the masses of all the isotopes of an element. I also understand that there are about 26 elements that are ...
1
vote
1answer
400 views

Does the van der Waals force not affect the alkali metal 's trend of decreasing melting points down the table? [duplicate]

Melting and boiling points increase further down the halogen group, but they decrease further down the alkali metal group. I know that the former's trend has to do with the van der Waals force, but I ...
1
vote
1answer
54 views

Is there a blanket term for all variants (both nuclides and ions) of a chemical element?

I'm hoping to catalogue the various nuclides and oxidation states of an element but can't find a single term that describes them all, save for "chemical element variations". Is there a specific term ...
16
votes
1answer
83k views

What is the melting point of diamond?

Textbooks and the online reference differ about this and there are more than two answers.
-1
votes
1answer
124 views

How to interpret detection limits

I am learning about different analytical methods such as Atomic Absorption Spectrscopy and Atomic Emission Spectroscopy and I'm having a difficult time understand how to interpret the detection limits ...
6
votes
1answer
7k views

What makes elements radioactive?

I know that certain elements like plutonium and certain isotopes of caesium are radioactive but what gives them this ability? If it's their electron/proton/neutron arrangement, what makes that ...
-1
votes
1answer
650 views

Why is the number of protons and neutrons equal to the atomic mass rounded?

The mass number is defined as the NUMBER of protons and neutrons. Electrons aside, why does the number of protons and neutrons equal the atomic mass rounded to the nearest whole number? That would ...
0
votes
3answers
2k views

Why are there only less than 120 elements out there ? [duplicate]

Why stop at 118 , Why aren't any more stable elements possible ?
10
votes
3answers
2k views

Why isn't neptunium used in nuclear reactors in nuclear power plants?

Why isn't neptunium used in nuclear reactors in nuclear power plants? Uranium is, and plutonium is. But neptunium isn't and it is in the middle of them. Is it like it is too hard to make it do ...
7
votes
3answers
9k views

What can be used as an electrolyte in water to perform electrolysis other than salt?

I am looking for an electrolyte to use in water to perform electrolysis. It can't be salt, as salt ($\ce{NaCl}$) would cause the chemical reaction of $$\ce{2H2O + 2NaCl -> Cl2 + H2 + 2NaOH}$$ or ...
-1
votes
1answer
191 views

Why atomic mass is taken in comparison?

The definition of atomic mass says that it is the mass of one atom of the element with respect to 1|12 of the mass of carbon-12 atom. My question is that why there is need to compare the atomic mass ...
-4
votes
2answers
2k views

Gold Half-Life and the Longevity of Gold Curiosity [closed]

I was curious if the half life of Gold is 186 Days, then why does it 'Last forever' ... Wouldn't the ancient Egyptian gold artifacts be decayed to lighter elements by now like platinum? I know gold ...
0
votes
1answer
45 views

What transition metal ions form without oxidant in water pH 7? [closed]

I am not sure how many transition metals will ionize without oxidants, where could I learn this?
1
vote
1answer
85 views

Library / function for computation of molecular mass / molecular weight in C

We are looking for a function to be used for computing the molecular mass / molecular weight / formula weight in C, either in a library or standalone. So far we have found the following ...
5
votes
5answers
985 views

Can halogens exist in their elemental state in nature?

Question 7 from the 2015 Australian Chemistry Olympiad was: Which list below gives non-metals that can be found in their elemental form in nature? (a) neon, phosphorus, fluorine (b) helium, hydrogen, ...
1
vote
0answers
55 views

How did the atomic number and atomic mass of elements discovered? [closed]

Elements are small for our naked eyes.so,how did the discovery of its atomic number and mass number took place?
2
votes
0answers
2k views

Why there is an exception in melting and boiling point in p block?

Why is the boiling point and melting point of 15th group and 16th group has an exception? We know that as molecular mass increases boiling point and melting point also increase. So, down the group 15 ...
1
vote
1answer
322 views

How to test for halides without ammoniacal silver nitrate solution? [closed]

If I have an halide e.g magnesium iodide, how can I test what halide the compound contains? I understand there is a method using silver nitrate and ammonia but what other methods are there?
0
votes
1answer
687 views

How to experimentally measure number of protons or electrons in an element? [duplicate]

How can one measure the numbers of protons or electrons (the atomic number) in a substance? Like if the element I examine is carbon I expect the result to be 6. Preferable a simple experiment which ...
10
votes
3answers
43k views

What is the difference between "molecular mass", "average atomic mass" and "molar mass"?

I don't understand the difference between "molecular mass" and "average atomic mass". They seem like the same thing to me. Is it that average atomic mass is just the weighted average of the "weights"/...
0
votes
0answers
516 views

Why are most atoms solids or gases but not liquids at room temperature? [duplicate]

Of all the elements of the periodic table, "most" elements with valences of four or less are solids, with most of these being either "metals" or "semiconductors." On the right hand side of the ...
10
votes
1answer
9k views

Why is arsenic more chemically similar to phosphorus than is nitrogen?

Why is arsenic more chemically similar to phosphorus than is nitrogen (to phosphorus)? I thought that it may be because both phosphorus and arsenic have d orbitals (albeit one has one that is filled ...
5
votes
2answers
238 views

How do I correctly typeset metastable radionuclide symbols?

Does anyone know if there is an officially sanctioned way to typeset symbols like technetium-99m (99Tcm or 99mTc)? I have seen both, although in more recent publications, I think, the latter ...
3
votes
0answers
408 views

Can CO2 be cracked by electrolysis? [closed]

What can be added to liquid $\ce{CO2}$ to lower the electricity needed to crack $CO_2$ ? Answer: Zirconium dioxide What form and temperature of $\ce{CO2}$ is best to crack with or without Zirconium ...
1
vote
1answer
270 views

Why does it yield iron(II) chloride instead of iron when copper meets iron(III) chloride? [closed]

Complete the equation: $$\ce{Cu + FeCl3 -> ? + ?}$$ I wrote $\ce{CuCl2}$ and $\ce{Fe}$, but it turned out to be $\ce{Cu}$ and $\ce{FeCl2}$. I really wonder why.
-1
votes
1answer
611 views

Elements in the lanthanide and Actinide series [duplicate]

How many elements are there in lanthanide and Actinide series? My big doubt is does the 57th element Lanthanum and 89th element Actinium include in it? In some periodic table the entire 57-71 is ...
0
votes
1answer
331 views

Have we found stable, super-heavy elements?

Have we found a stable super heavy element or created one in a lab, or are they still hypothetical?
0
votes
1answer
411 views

Is lanthanum a lanthanoid? [duplicate]

Is lanthanum classified as lanthanoids? If yes, then can somebody explain in detail why La has 6s2 5d1 as its electron configuration and Ce has 6s2 4f1 5d1?
10
votes
2answers
6k views

Elements which do not form oxides

I had thought that this question would be easy to answer but my searching has been unsuccessful in finding a clear answer. For the metals, I expect that they all form oxides. Some very readily, e....
2
votes
2answers
549 views

Does mercury have an NFPA 704 classification?

I've searched on a lot of websites if elemental mercury (Hg) has an NFPA classification but I can't find any. Does mercury have an NFPA classification?
12
votes
1answer
1k views

Confusion over boiling point of gallium

I am completing a project on gallium, and I need to include its boiling point. I thought that this would be fairly simple to look up, however, it appears that different sources quote different ...
-2
votes
3answers
4k views

What is the element with the greatest first ionization energy?

Identify the element with the greatest first ionization energy. (A) Ce (B) C (C) Cl (D) Ca (E) Cs The book says the correct answer is (B) with such an explanation: First ionization ...
2
votes
2answers
3k views

Pure substances have only one kind of atom

I read in a book recently that no substance is ever totally pure, even if we take great care to separate it from other substances. And also that pure substances contain only one kind of matter. But I ...
1
vote
1answer
17k views

how many electrons are in the second subshell of this element?

first of all sorry if I have some mistakes in my "chemistry words", I'm Iranian and I know the Persian terms but only some of the English ones. So suppose we have an element (x) with the atomic ...
1
vote
2answers
3k views

Which element has larger atomic radius -- beryllium or xenon?

I say that xenon radius is smaller comparing to beryllium, but my friend says otherwise. What I think is that xenon is down in periodic table comparing to beryllium (3 periods down) and it's far ...
5
votes
1answer
231 views

Phospors and Phosphorus

I'm not a chemist. I understand that phosphorus comes in multiple forms, one of which is white, volatile, and highly toxic. I know that phosphors come in multiple chemical forms, two of which are ...
19
votes
2answers
2k views

Do the names of some elements have anything to do with planets?

There are elements like neptunium and plutonium in the periodic table. Did their discovery have anything to do with Neptune and Pluto? Or are they randomly assigned with such names?
20
votes
1answer
10k views

Why is beryllium transparent to x-rays?

Beryllium has other fancy applications. It is transparent to x-rays, so it's used in the windows of x-ray tubes, which need to be strong enough to hold a perfect vacuum, yet thin enough to let the ...
10
votes
2answers
38k views

Is astatine a non-metal or a metalloid?

Is astatine a non-metal or a metalloid? A metalloid is an element which exhibits some of the properties of a metal as well as those of a non metal.
9
votes
1answer
3k views

Identification: was this gallium or mercury from broken thermometer?

I had accidentally broken a thermometer against my computer screen, resulting in the splash of the silvery substance seen below: I cannot remember whether the thermometer is a mercury-free ...