One of the singular accomplishments in science was the assembling of chemical elements into what is known today as the Periodical Table. This was done before computers and many of the other measurement devices we take for granted nowadays. Dmitri Mendeleev, a 19th century Russian professor of chemistry, did much of the heavy lifting toward the placement of the known elements, 63 at that time. Currently, the Table lists 118.
Chemistry, the branch of science concerned with the stuff comprising the universe (matter) classifies it in two groups: elements and compounds. Elements (atoms) are the basic building blocks of matter, so to speak. Compounds are chemically bonded combinations of two or more elements. Whereas elements number in the low hundreds, there are nearly an infinite number of compounds. Examples: Dihydrogen monoxide (the familiar H2O), carbon dioxide (CO2), sodium chloride (NaCl), chlorine (Cl2), sodium bicarbonate (NaHCO3), etc, etc.
Elements, themselves, are comprised of three “subatomic” particles: protons, electrons and neutrons (full disclosure: there are numerous other particles out there, but for simplicity, we’ll just consider these three). Protons and neutrons are the “load bearing” particles, each having about 1,800 times the mass (weight) of electrons. Protons also carry an electric charge of +1, while electrons (despite their light weight) carry a single negative charge. Plus is attracted to minus, while like charges repel. Sort of like a magnet. Elements and compounds are neutral, overall, so the number of protons and electrons must be equal to each other. Neutrons have no charge.
By the mid 19th century, chemists were able to weigh elements. Mendeleev ranked them in order of weight, starting with hydrogen. He found that the elements, if placed in order, had similar chemical behaviors in repeating columns of eight. For example, lithium (#3) seemed to behave chemically in the same manner as sodium (#11). Both elements reacted with water almost violently. By contrast, helium (#2), and neon (#10) seemed totally unreactive. Fluorine (#9) and chlorine (#17) were nearly identical. A serious break in the pattern occurred with argon, the 18th , an unreactive gas like helium and neon, and potassium, the nineteenth, which behaved like lithium and sodium. The other load bearing particle, the neutron, had not been identified at the time Mendeleev first assembled the table. Turns out that argon has a greater number of neutrons than potassium, making it heavier. The two elements switched places in Mendeleev’s scheme.
Mendeleev’s work illustrates what is often referred to as the scientific method. One does something like assembling known elements working with what is known at the time. As new info becomes available, one modifies the “hypothesis”, or working model, to explain anomalies, or draw more accurate conclusions. A similar process is at work in dealing with the Covid-19 pandemic.
Atoms are extremely small.. They take up only a tiny amount of space (room).
Protons and neutrons are concentrated, cheek-to-jowl within the center of the atom, aka the nucleus. Electrons are found in regions surrounding the nucleus (think of planets orbiting the sun, but don’t take this too seriously). The electron regions, so to speak, comprise the vast majority of the space the atoms occupy. If one pictures all those positive charges jammed into the tiny space (nucleus), how the hades does the thing not fly apart? ( remember, like charges repel each other). Might the electrically neutral neutrons sort of keep the pieces together? (This is why we need physicists…..)
Meanwhile, electrons form the chemical “bonds” to make compounds, But only the outermost electrons. We call them “valence” electrons. Consider the 11 electrons in the sodium atom, Only one of these is a valence electron, and capable of entering into a chemical bond. On the other hand, chlorine has 17 electrons, 7 of which are valence. Turns out that if sodium donates an electron to chlorine, a compound called sodium chloride is formed. Voila! Table salt! Moreover, the resultant chlorine now has 18 electrons, same as (chemically inactive) argon. If sodium loses an electron, its structure sort of becomes neon, also a fat-dumb-and-happy camper.
Where am I going with this? Science is the thought process humans have used since the beginning of time to figure out the world around us. The reality is that “truth” is dynamic and constantly changing, as we learn new stuff. This goes far toward understanding why the covid pandemic nature and facts seem to change constantly. As new stuff is learned, the “plan” needs to be changed. A popular musical a few decades back featured a song called “Stop the world, I want to get off”. A lot of us, I’m sure, feel this way at times.
We’ll talk more soon. We need to consider chemical bonding, where it’s really at.
Rogernarc 