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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What Can I do With Captured Co2 (in Gas Form)? [closed]
Can I send It to a Scientist? and If so, What Scientist? Can Someone Help me Get in Contact with one? Thanks! (I don't need to be payed for it, its free)
4
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1answer
840 views
“Estrontium” on poster
I was looking at a poster for an international chemistry olympiad. Its background contains some random elements as periodic table tiles.
One of them said "Estrontium." A google search returned ...
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0answers
38 views
Properties of chemical elements: Monatomic or compounds?
I have this question which is probably very basic: when we see those tables of chemical elements properties, such as melting point, heat capacity etc... are these defined for the monatomic form, or ...
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1answer
49 views
What is the most common element in the human body? [closed]
I was wondering that since H2O was 66% of the human body, hydrogen would be the most. But apparently carbon is. Can someone explain that?
8
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1answer
135 views
Reasons for low melting point of gallium
J.D. Lee writes in Concise Inorganic Chemistry:
Gallium has an unusual structure. Each atom has one closest neighbor at a distance of 2.43 Å.
This remarkable structure tends towards discrete ...
11
votes
3answers
980 views
Elements other than carbon that can form many different compounds by bonding to themselves?
My textbook says the following:
Unique among the elements, carbon can bond to itself to form extremely strong two-dimensional sheets, as it does in graphite, as well as buckyballs and nanotubes.
...
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0answers
23 views
Why isn't lithium a diatomic element? [duplicate]
Lithium seems to be a perfect fit to be a diatomic element. Could two Li atoms form a bond to become a diatomic element?
0
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1answer
90 views
Does dilithium exist? [duplicate]
Lithium has two electrons in $\mathrm{1s}$, filling the first energy level; and one valence electron in $\mathrm{2s}$. Could two $\ce{Li}$ atoms form a bond to create $\ce{Li2}$; like $\ce{O2}$ or $\...
2
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1answer
41 views
Two different electronic configurations for cerium
Depending on the textbook there are two different electronic configurations stated for cerium. On the one hand
$$[\ce{Xe}]\mathrm{4f^15d^16s^2}\quad$$
and on the other hand
$$[\ce{Xe}]\mathrm{4f^...
1
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0answers
73 views
Why should I care about the highly radioactive elements after fermium? [closed]
After element 100, fermium, there are a bunch of highly radioactive elements like fermium, tennessine, and oganesson, and others. These elements are to radioactive to store, they will instantly ...
1
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1answer
47 views
Does one atom of an element show the properties of a bulk of that element? [duplicate]
For example, does one atom of gold have a golden color?
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1answer
62 views
Is there an element with no liquid state? [closed]
I know this question might be dumb but, is there an element that will go directly from solid to gas, with almost no visible or no liquid state? Just a random curious question.
0
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1answer
41 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
votes
2answers
643 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
43 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
64 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
64 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
126 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
...
1
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1answer
87 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
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2answers
76 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
2answers
221 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 ...
1
vote
1answer
95 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
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1answer
49 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 ...
0
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1answer
297 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 ...
6
votes
2answers
710 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 ...
0
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3answers
290 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
64 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
55 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
747 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
36 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
277 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
vote
1answer
59 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 ...
1
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0answers
42 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
136 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
75 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
votes
0answers
156 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 ...
1
vote
2answers
131 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
364 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
112 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
votes
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
931 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 ...
0
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1answer
226 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
2k 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
2k 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
125 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
2k 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
2k 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 ...
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1answer
91 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 ...
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0answers
76 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
128 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, ...
