Questions tagged [elements]
A pure chemical substance consisting of a unique type of atom with a distinguished by its atomic mass.
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Which of these models represent a binary lithium compound and with which element? [on hold]
A chemist performs reactions that produce binary lithium compounds. These elements include sulfur, chlorine, nitrogen, fluorine, selenium, oxygen, and iodine.
I think the elements are chlorine ...
0
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1answer
29 views
What does it mean that an electron quantum numbers are n1= 4 - l1?
I'm trying to solve some exercises from the 2017 IChO, and the problem 6-A1 states that
in first ionization, an electron with the quantum numbers $n_1 = 4 - l_1$ is removed.
Now, I've never seen ...
4
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2answers
596 views
Chemical composition of seawater
Is it true that the sea water is composed of about $86\%$ oxygen, $11\%$ hydrogen and $3\%$ of minerals? The chemical formula of water is $\ce{H2O}$ (two hydrogen and one oxgen) that shows that the ...
0
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1answer
32 views
Reactivity and its meaning
When we say that “potassium” is reactive, are we referring to a potassium atom or bulk potassium as in the solid metal? In other words does “potassium” refer to a type of atom or an agglomeration of ...
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1answer
57 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, ...
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0answers
31 views
Is it possible to determine the properties from a element based on the atomic structure [duplicate]
as the title already says i am trying to figure out if there is a way to determine the properties from the atomic structure of an element.
So lets say we have the following water atom:
the atomic ...
4
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1answer
54 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?
3
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1answer
123 views
Is there a case when an atom of some element (e.g. carbon) does not have its expected number of protons (e.g. 6)?
Page 12 of the Study Guide for Campbell Biology, 11th Edition has the following question:
A carbon atom has 6 neutrons. How many protons are present in the nucleus of a carbon atom?
A. 12
...
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0answers
24 views
How to use Hund third rule for cases like Nb, Ru, Rh, Pt?
How do I use Hund third rule to determine the value of $J$ for ground state for cases like Nb, Ru, Rh, Pt where there is 1 electron in s orbital and then an incomplete p orbital, and besides, S nor L ...
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1answer
66 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?
2
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2answers
66 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-...
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1answer
93 views
What is the true depiction of the periodic table?
Normally with the periodic table the lanthanide series is separated out because it's long and would make the table wide. I looked for an expanded version and found this:
I found it kind of strange ...
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0answers
37 views
What does the presenter in this video mean when he described the possible hazards of pure Astatine?
In this Youtube Video (linked to the specific time) a presenter is describing various elements in a "real life" periodic table. At one point, "The Professor" picks up an acrylic glass containing ...
1
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1answer
68 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
48 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 ...
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1answer
110 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 ...
5
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2answers
482 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 ...
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3answers
180 views
Why are there only less than 120 elements out there ? [duplicate]
Why stop at 118 , Why aren't any more stable elements possible ?
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1answer
46 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 ...
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1answer
46 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 ...
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votes
2answers
403 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
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1answer
30 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?
5
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5answers
196 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, ...
1
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1answer
53 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 ...
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0answers
32 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?
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1answer
89 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
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1answer
52 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 ...
0
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0answers
58 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 ...
0
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0answers
36 views
Unable to understand properties of elements [duplicate]
Sorry about the daft question, but I can't understand this part of my chemistry book:
It says the atomic size is decreasing (from sodium to argon), yet the atomic number goes: 11, 12, 13, 14, 15 ...
1
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2answers
92 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.
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1answer
258 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 ...
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0answers
28 views
Why is there such a big difference between the levels of precision that we know gallium's boiling and melting points to? [duplicate]
For example, Wikipedia lists the melting point of gallium at the very precise 302.9146K while it lists its boiling point at the much less precise 2673K. Is this down to experimental issues or is there ...
0
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1answer
82 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?
9
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2answers
2k 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....
12
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1answer
834 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 ...
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1answer
173 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?
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2answers
1k 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 ...
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2answers
1k 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
100 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 ...
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3answers
1k 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 ...
9
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1answer
1k 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 ...
1
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1answer
89 views
Can rays be considered a type of “element”? [closed]
First of all, I hardly know any chemistry, so let's get that out of the way.
I have been wondering lately, from a "common sense" point of view (owing to my lack of knowledge), that since air cannot ...
1
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0answers
67 views
How can scientists measure the electron affinity and the ionization energy of an element? [closed]
I am pretty curious about the method that the scientists use to measure the electron affinity and the ionization energy of an element. If someone knows about it, please tell me.
0
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1answer
124 views
How right is defining elements with the number of protons? [closed]
Atomic number is the number of protons a certain atom has. It's the defining attribute of a certain element. But, How right is that?
From the viewpoint of chemistry, the definition is right. Because, ...
1
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1answer
70 views
What metal is under the stainless layer when it wears of?
I have this belt for several years now and the belt buckle is naturally subject to wear and tear.
On the most exposed spots the outer layer is now completely worn of and I wonder
Is this an example ...
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1answer
97 views
Island of Stability - Why not smash massive elements?
Why haven't scientists (or at least any reports of scientists) smash really heavy stable (or stable-enough) massive elements to produce heavier elements in the proposed island of stability?
Not being ...
0
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2answers
258 views
Is consumption of chlorine, like fluorine, harmful to bones? [closed]
Is consumption of chlorine harmful to bones ?
I know fluorine consumed with water can cause fluorosis to bones and joints.
Can chlorine, a similar halogen like fluorine, also cause damage to bones ...
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1answer
4k views
Whats the difference between 2O and O2 [duplicate]
I just saw something in a chemistry lesson what got me confused.
What is the difference between $\ce{2O}$ and $\ce{O2}$?
Thanks for the help!
3
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0answers
131 views
Why does zinc turn dark?
So I casted a zinc ingot around a week ago and I also casted 2 zinc ingots yesterday. After observing the two side by side I noticed that the older zinc ingot was darker colored, then I went and ...
7
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1answer
790 views
Bonding of Lithium and Argon
I saw a meme that was joking around about Lithium and Argon bonding (see pic below). It got me wondering: Can Lithium and Argon bond in any circumstance?
