Tag: science & technology

The radioactive decay series (uranium series, actinium series, thorium series) are also known as the 'actinide series', not the 'lanthanide series'. Lanthanides are the 15 elements from lanthanum to lutetium and are not radioactive decay series.

The chemical symbol for mercury is Hg, which comes from its Latin name 'hydrargyrum' meaning 'liquid silver'. Mg is magnesium, Fm is fermium, Mc is moscovium.

The halogens in order are: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At). Iodine (I) is the fourth halogen in this periodic table group.

Antimony's Latin name is Stibium, which is why its chemical symbol Sb doesn't match the English name. Cuprum is copper (Cu), Stannum is tin (Sn), and Plumbum is lead (Pb).

In fluid mechanics, viscous force follows Newton's law of viscosity: F = ηA(dv/dy), where η is viscosity, A is area, and dv/dy is the velocity gradient perpendicular to flow. It's independent of mass, temperature, or charge gradients.

Pepsin is a digestive enzyme secreted by gastric chief cells in the stomach lining. It breaks down proteins into peptides and works optimally in the stomach's acidic environment (pH 1.5-2). The liver produces bile, kidneys filter blood, and spleen is part of the immune system.

In K3[Fe(CN)6]: K is +1 each (total +3), CN is -1 each (total -6). For neutral compound: +3 + Fe + (-6) = 0, so Fe = +3. This is ferricyanide; the related ferrocyanide K4[Fe(CN)6] has Fe(+2).

Microsoft developed the Windows operating system, first released in 1985 as a graphical shell for MS-DOS. AT&T developed UNIX, Sun Microsystems developed Java and Solaris, and IBM developed OS/2 and mainframe systems.

Linus Torvalds created the Linux kernel in 1991 as a university student in Finland. Bill Gates co-founded Microsoft, the US Army developed early ARPANET (internet precursor), and Dave Packard co-founded Hewlett-Packard.