In my experience its better to just tell it once and then let the reader make the analogy for himself.

In other words, an atom of hydrogen is a unit of hydrogen—the smallest amount of hydrogen that can exist. For scale, if an atom were the size of your bedroom, its nucleus would be the size of a speck of dust (unless you’ve got a really big bedroom. Singly ionized oxygen is very close to nitrogen, it will readily bind three hydrogen atoms to produce an ammonia shaped H3O+ molecule and will pair up into strongly bonded O2. Unfortunately the term is somewhat misleading, as we’ll see, for these “particles” have some properties that aren’t very particle-like at all.The number of protons and electrons within a neutral atom are equal, thus, the atom’s overall charge is balanced. When you consume dairy products your digestive system breaks down the food into components small enough to cross into the bloodstream. According to the octet rule, magnesium is unstable (reactive) because its valence shell has just two electrons. What is the main source of the chemical difference between an atom from one element and an atom from another element?

A famous example is that the proton size effectively grows (not a lot) as you increase the energy of the particles that you are scattering off of it. Again, a look at the periodic table reveals that all of the elements in the second row, from lithium to neon, have just two electron shells. I certainly don’t have an ideal way to draw it that wouldn’t be misleading, and experts still argue about what is the best way to think about it. It conveys the very rough idea of what an atom is like: it has a certain number of electrons (drawn here in blue) on the outside, in orbit around a central atomic nucleus. PET highlights areas in the body where there is relatively high glucose use, which is characteristic of cancerous tissue.None of these is really entirely accurate as far as it describes the equations we use, and we don’t know the equations are giving us quite the right picture for what nature is doing. Magnesium’s 12 electrons are distributed as follows: two in the first shell, eight in the second shell, and two in its valence shell. I like Figure 2 very much, but a variant of it showing the balloon-like shapes of the orbitals might be a useful companion. It is a veritable cliche borne of quantum theory’s founding fathers that to utter an understanding of atomic reality based on quantum theory is to reveal one’s ignorance.

Helium, as well as larger atoms with eight electrons in their valence shell, is unlikely to participate in chemical reactions because they are stable.Maybe all the baggage carried along with the word, “particle” is an obstacle to a deeper understanding. What that means is that on a given atom, each electron has a unique set of quantum numbers, and they “want to stay as far away” from any other electron as they can. If that sounds strange, it’s not because you’ve misunderstood; it is strange, and hard to think about.

What is the main source of the difference in chemistry between an atom from one element and an atom from another element? I understand why you’re describing the atomic number in terms of the electron count, because it’s what matters for chemistry, but it seems to me it opens up the possibility of a lot of confusion when it comes to ions.

One of the most advanced uses of radioisotopes in medicine is the positron emission tomography (PET) scanner, which detects the activity in the body of a very small injection of radioactive glucose, the simple sugar that cells use for energy. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. To a non-scientist like myself, size is dependent on distance from whatever is being measured – a house looks smaller seen from a distance. In any case, the equations we use give correct predictions for atoms and how they behave; the issue in question is how you interpret what the equations signify, which is inevitably ambiguous. For example, in the past, the only options for a patient with one or more tumors in the liver were surgery and chemotherapy (the administration of drugs to treat cancer).