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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Predict the valence configuration of this element using the first five ionization energies

If the first five ionization energies of an element are, respectively: $\pu{1.09 kJ/mol}$, $\pu{2.35 kJ/mol}$, $\pu{4.62 kJ/mol}$, $\pu{6.22 kJ/mol}$ and $\pu{37.83 kJ/mol}$, to which group of the ...
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Is there an accurate displacement reaction series including every element?

I have had the hardest time finding this information out. I would like to know the displacement order of every conductive element on the periodic table but I haven't found a single source of data that ...
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How can I determine whether sp-mixing occurs for heteronuclear diatomics?

I'm trying to draw out the molecular orbital diagram of nitrogen monoxide (NO) but I do not know whether sp-mixing occurs. This is important in order to determine the arrangement of molecular orbitals....
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How can chlorine be 'only' the third-most electronegative element yet have the highest electron affinity?

From Wikipedia: It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the Pauling scale, ...
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Oxidation number approximately

I argued with my lecturer when he is saying that during the calculation of oxidation number, and your answer give you like 3.46 you can approximate it to whole number, I know tell him NO that if the ...
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Probability of forming dihydrogen with molecular weight 3 [closed]

During a lecture, my professor told us that the probability $P$ to form a hydrogen molecule $\ce{H2}$ with mass number 3 could be calculated out of the abundances, $\gamma$, of the isotopes of this ...
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35 views

Could there ever be a way to safely handle visible amounts of elements like astatine, francium, or protactinium? [closed]

This is something I'd actually be interested in doing if possible. I've asked about artificial stability here https://physics.stackexchange.com/questions/584595/could-there-at-least-theoretically-ever-...
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How would someone in 1917 describe elements 43, 61, 72, 75, 84, 85, 87, 89, and 91? [closed]

https://books.google.com/books?id=aaELAAAAYAAJ&printsec=frontcover#v=onepage&q&f=false Notice the list of elements on pages 62–63. It includes a short description of each element's "...
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Which allotropes of sulfur exist naturally?

I'm writing a paper on chemistry and I would like to know which allotropes of sulfur exist naturally. I've searched on the Internet but I haven't found anything about natural sulfur allotropes except ...
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Can someone help me figure out what the noble gas configurations for zirconium and holmium are? [closed]

I am currently working on noble gas configurations in chemistry and I am having a hard time understanding why I got two questions wrong on a practice. The instructions for the practice are here: Write ...
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Why can't Astatine form a diatomic homonuclear molecule like the rest of the halogens? [duplicate]

My understanding of chemistry is very elementary. I was reading about diatomic molecules and found the following image showing which elements can exist as diatomic (2 atoms) homonuclear (same element) ...
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Is there a standard scholarly reference for lattice constants of crystals of the elements?

I need to discuss the lattice constants of bulk crystals of several metal and semiconductor elements. I can find plenty of tables and numbers that are probably "close enough" but for a paper ...
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A theoretical chemistry question about elements and their presence over time [closed]

I'm not a chemist myself, but I can't think of a better place to get some insight about elements and chemistry than from people who live and breathe it here on stackexchange. This is not any kind of ...
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How do you know what elements will bond in a reaction? [closed]

I know all about the types of reactions, synthesis, decomp. etc., but when a bond is broken, how do you know that the free element will bond to another molecule? Is it because that element has a ...
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How did Mendeleev know elements from compounds or mixtures?

I read that Mendeleev initially thought didymium was an element, but it was actually a mixture. How did he know the rest of the chemicals in the periodic table were elements and not compounds, ...
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Chemical elements or compounds with yellowish white color [closed]

Are there chemical elements or compounds that have a yellowish white (cream) color in their natural state?
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How do scientists know they have discovered an element? [duplicate]

I have a background in math not chemistry and perhaps this question is inappropriate but I will try. I read that after pitchblende was discovered Martin Klaproth in 1879 a latter date discovered that ...
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Is there any elemental molecule which does not react well with anything but oxygen? [closed]

For example, phosphor reacts with oxygen but it also easily reacts with many halogens, metals, etc. Is there any elemental molecule that doesn't react well with almost anything but oxygen?
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Similarities between Co and Ni [closed]

Elements $\ce{Co}$ and $\ce{Ni}$ share many similar/same properties and usually if one of them is an example of some group (e.g., ferromagnetism, same possible oxidation states, packing fraction and ...
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Why do elements have mass numbers? [duplicate]

I don't really understand why an element has a mass number, I thought that an element has several isotopes, each with a different mass. Is my understanding correct: The mass number of an element ...
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2answers
77 views

What is really the number in the periodic table? [closed]

I learning basic chemistry and i have a doubt. I have this definitions Molar mass: Is the mass of $6.022\times10^{23}$ atoms of a chemical element and its unit of measurement is $\mathrm{g/mol}$. ...
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Solution for Electroplating Selenium?

I need to electroplate selenium onto a conductive metal (for an experiment). The end goal is a thin film of pure, elemental selenium. Unfortunately I can't find anything on the internet: Ideally, I'd ...
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Why aren't Boron and Aluminium assigned to group 3 of periodic table? What determines the group? [closed]

I've been curious about this 3D representation of the periodic table "Mendeleev's Flower" and was trying to study it, wondering if it reveals any regularities that are not obvious from classic ...
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Why is the number of covalent bounds typically formed by an element equal to 8 minus the group number? [closed]

Why would the number of covalent bounds typically formed by an element equal to 8 minus the group number? E.g for C, we have 8-4 bonds, for Cl, 8-7 bonds
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Exceptional electromagnetic properties of lanthanide series elements

Why do so many lanthanide series elements have exceptional electromagnetic properties? They can form strong magnets and are also used in superconducting applications. The number of elements in the ...
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Is it tennessINE because it has 117 electrons or because it behaves like a halogen?

The NPR News podcast and transcript The Convoluted Story Of How The First Atoms Of Tennessine Were Created includes the following exchange between science reporter Joe Palca and Oak Ridge nuclear ...
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How does a vitamin differ from a mineral [closed]

At the molecular level, I would like to know fundamentally how does a vitamin differs from a mineral. I understand both have, to say, Fe (Iron), then what exactly makes it a mineral Iron or a vitamin ...
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124 views

The “nose” of the periodic table [closed]

My teacher said that on the periodic table there is a "nose" formed by Al, Zn, Ag, and Cd. She said that they are all fixed charged (+3, +2, +1, and +2 respectively), and said that if I write them in ...
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Crystal structures of heaviest nuclides' compounds

What is the heaviest element of the periodic table for which there is a compound whose crystal structure has been completely resolved by X-ray diffraction?
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What element has good conductivity but is also brittle? [closed]

I'm confused by what element(s) can be identified to have these properties. The following is text from my 2019-2020 Kaplan MCAT General Chemistry book under the metalloids section Silicon (Si) has ...
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Why does period 3 of the periodic table contain 8 elements instead of 18?

Period 1 of the periodic table contains 2 elements ($1s^1$ and $1s^2$). Period 2 contains 8 elements ($2s^1$, $2s^2$, $2p^1$, $2p^3$, ..., $2p^6$). By the same argument, period 3 might contain 18 ...
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Isotopes and elements [closed]

this is a gold bar. If we look at its structure, will we see that there are atoms that have a different number of neutrons (aka isotopes) (as far as I'm concerned, an isotope is an atom with a ...
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Predicting atomic weight and density of calcium [closed]

I have a question from school: Assuming that the element Ca had not been discovered, predict using the properties of the known element surrounding Ca its own properties such as its atomic weight ...
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541 views

Why does zinc sulfide glow when hit by electrons? [duplicate]

In cathode ray tube experiment in order to check the direction of flow of electrons a hole was made in a note and behind it phosphorescent material zinc sulfide it was coated. Why does zinc sulfide ...
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Electrolysis of a calcium salt in polar aprotic solvent

If i found a calcium salt that is soluble in acetone or ethyl acetate, which are polar aprotic solvents, and attempted electrolysis, what would happen? Since polar aprotic solvents are used in metal-...
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Doubt on Element [duplicate]

I read the definition of element: Element consists of only one kind of atom and cannot be broken down into a simpler type of matter by either physical or chemical means. Then as per definition, $\...
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1answer
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“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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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?
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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 diatomic ...
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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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300 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 $\...
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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^...
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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 ...
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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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803 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.
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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 ...
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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 ...
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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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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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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?

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