7

Since there were no further suggestions, I decided to use the references from my comment in an answer, which, I believe, is element 99, einsteinium. Both single crystal x-ray diffraction (SCXRD) and powder x-ray diffraction (PXRD) have certain sample requirements/limitations: Mass/amount PXRD: lower limit is in micrograms region, ideally at least a couple ...


4

While your question refers to human metabolism, it should be noted that bacteria can use elemental hydrogen, elemental sulfur, and elemental iron as energy sources: See Wikipedia's page on Microbial metabolism, particularly the section on chemolithotrophy. If any of these bacteria are found in the human gut, and their metabolic processes support our own (...


3

Atomic mass is not exactly proportional to the mass number of the nucleus. Let's look at all the complicated factors that appear in one little atomic mass value: Particles: Protons and neutrons do not have exactly the same mass Binding Energy: The mass of a nucleus is less than the sum of the individual protons and neutrons because energy is lost (so mass ...


3

Since you are asking about vitamins vs. minerals, I assume what you mean by mineral is a "dietary mineral" (as opposed to the more typical meaning of mineral, which is a naturally-occurring inorganic compound). So: A dietary mineral is an element that is essential for life (e.g., K, Ca, Fe, Se, Cr, P, I, Cl, Mo, etc.), and is required in small quantities. ...


3

Instead of your definition, which can be misleading if you are a beginner, I would use the Wikipedia definition instead. You see that an element is better defined using the atomic number, i.e. the number of protons in the nucleus: we define elements as those entities which have the same number of protons in the nucleus. That's why we can distinguish between ...


2

Whether a "metalloid" is both brittle and a good conductor depends on what you mean by "metalloid", which varies in literature, what is a "good" level of (electrical) conductivity, and even what exactly you mean by "brittle" versus "ductile". Silicon, for instance, is only a semiconductor, with much less electrical conductivity than metals, when pure. ...


2

All of these elements can form compounds in other oxidation states. Aluminium forms some compounds in the +1 state (e.g. see the section in https://en.wikipedia.org/wiki/Aluminium_iodide), as does Zinc (see the section in https://en.wikipedia.org/wiki/Compounds_of_zinc) and Cadmium (e.g. https://en.wikipedia.org/wiki/Cadmium(I)_tetrachloroaluminate). But ...


2

Back in 1933, John Drury Clark published 1 his "race track" periodic table that subsequently became famous as the cover of Life magazine in 1949: Looks like B and Al are nicely positioned. Just need to add an outer track for elements 105 - 118, element names and symbols for elements 97 - 103 and element 41 is niobium, Nb. 1 Clark, John D. (November 1933). "...


2

So, what is this number really? the mass of one mol of the element or the sum of protons + neutrons? The number is the molar mass expressed in g/mol, i.e. stripped off these units. (The molar mass is the mass of a sample of the element divided by its amount of substance. This explains why the units are g/mol.) Alternatively, you can also say the number is ...


1

Cobalt and Iron ions are the only ones to produce colored complexes when mixed with thiocyanate ion $\ce{SCN^-}$. If you mix up a dilute acidic solution of Iron(III) Chloride $\ce{FeCl_3}$ and a similar solution of ammonium thiocyanate $\ce{NH_4CNS}$, a extremely dark red solution is obtained, due to a complex containing the ions $\ce{Fe^{3+}}$ and $\ce{SCN^-...


1

I'm not sure of any conventional ways of electroplating selenium, but you could use a technique such as magnetron sputtering to spray a thin film of selenium onto another metal. Heck, you could even use glass or wood if you wanted to do it that way. And if you're going for thin, this technique can get you some of the thinnest, smoothest layers of metal out ...


1

In a very general aspect we could think of the following, if $X$ was the more electronegative element, say group 14 - group 17 and $M$ was the less electronegative element, then if the compound $M_mX_x$ forms, $M$ would give its electrons to $X$ so $X$ can form an octett which is the most stable electron configuration. To get this octett at $X$ you will ...


1

First of all, one has to adopt an outdated concept of group number for the concept mentioned in the question to work. The group number of carbon, silicon, germanium ... is 14, not 4, per IUPAC. Reverting to the old definition (sometimes called main group), one notices that the old group number is equal to the valence electrons for the members of the group. ...


1

You could say that the period number tells you about the largest value of principal quantum number in which a electron is present. Electrons are filled according to $n+l$ rule. It states as $n+l$ increases, the energy of the orbital increases. If $n+l$ is the same, then the bigger $n$ has larger energy. So $\mathrm{4s}$ would be filled before $\mathrm{3d}$....


1

Gold has only one natural isotope: 197. There are artificial gold isotopes, but they do not end up in gold bars. Even if they did, their half life is measured in days so don’t expect much to remain after a year or so. The “structure” of the metal bar, or atomic arrangement, has nothing to do with its isotopic composition. Even if you were to measure ...


1

When we say that potassium is reactive, it is understood that it is more reactive than sodium. This can be easily demonstrated in classrooms by dropping a small piece (max 0.1 g) of those metals into a tub of cold water. Sodium reacts in a relatively calm way by melting and moving quickly at the water surface, yielding Hydrogen gas H2 which can be set on ...


1

One of the largest issues as to your question is Plutonium 244, or Pu-244. Its half-life is just over 80 million years, which (given the existence of thorium and uranium with much higher half lives) suggests that it like those other high-proton elements must have been originally been produced in supernovae and debated since then. Unlike the decay ...


1

Here is the IUPAC definition of an element: https://doi.org/10.1351/goldbook.C01022 A species of atoms; all atoms with the same number of protons in the atomic nucleus. A pure chemical substance composed of atoms with the same number of protons in the atomic nucleus. Sometimes this concept is called the elementary substance as distinct from the ...


Only top voted, non community-wiki answers of a minimum length are eligible