Chpt. 7, The Elements Flashcards
hydrogen
Hydrogen has only one valence electron, so it does weird chemistry. It can either gain electrons to form the H- ion or lose electrons to form the H+ ion. When you’ve got a bunch of gaseous hydrogen sitting around in big balloons, nothing much happens until you add energy – then it explodes. Think of hydrogen as the inexplicably cranky uncle of the periodic table family: It’s happy to sit quietly at the dinner table until it starts suddenly ranting about “them Commie bastards.”
alkali metals
In addition to their properties of low melting and boiling point and softness, these metals (which aren’t actually metals) also blow up when you put them in water.
Alkali metals form +1 ions when they react, which reflects the fact that they want to lose one electron to be like the nearest noble gas.
Solutions made with these elements are basic, which is another way of saying “alkaline”, which is pretty close to the world “alkali”, which is where they get their group name.
alkaline earth metals
Alkaline earth metals are like alkali metals, except that their properties aren’t as extreme. For example, they’re reactive, but they don’t blow up in water (calcium does, however, kind of fizz a little). They have low melting and boiling points, but not really all that low. They do form ions with a +2 charge, which reflects their desire to lose two electrons to be like the nearest noble gas.
the p-block, groups 13-18
Elements in the p-block are a mixed bag. Some are metals, some are nonmetals, and some are metalloids. If you’re looking for an element with some property in particular, look no further than the p-block.
group 13, boron’s group
The elements in boron’s group don’t have much in common with each other because boron is a metalloid and the rest are metals. Aluminum is probably the most important element in this group, being widely used to make aluminum cans, industrial stuff, and deodorant.
group 14, carbon’s group
Carbon is a really important element that’s present in all biological systems. It’s commonly found as one of three allotropes: as graphite (a black sooty form), diamond (a really pretty clear form), and fullerenes (a form that’s also black and sooty).
Other important elements in this group include silicon (a metalloid that’s used to make computer chips), lead (which is used to make fishing weights and used to be used to make paint that contributed to the stupidity of small children), and tin (which is used to make solder and pewter).
Silicon is a metalloid in this group and is used to make computer chips and sand. Lead is used to make batteries, and tin isn’t really used for that much anymore except in the manufacture of those pewter figurines your grandma is so fond of.
group 16, the chalcogens
Oxygen is required for stuff to burn and also for animals to breathe. There’s a lot of it in our atmosphere, which is good news for us. Sulfur smells bad and is used to make sulfuric acid, and both selenium and tellurium are used in semiconductor production.
group 17, the halogens
The halogens are all unbelievably reactive. Fluorine is the most electronegative element so it will instantly strip electrons off of almost anything it comes into contact with, and the other halogens pretty much do the same thing, too. These elements are also pretty good at killing living creatures, which can be both good (when used to kill microorganisms in water) or bad (when used as chemical weapons).
group 18, the noble gases
This group contains the most stable elements out of them all (they have full valence levels); these elements are extremely unreactive.
terminology
Though the term “transition elements” technically refers to the d-block elements (which are the “outer transition metals” and the f-block elements (which are the “inner transition metals”), nobody actually ever uses these terms in the real world. If you want to sound like a real science guy, use the term “transition metals” to refer to the d-block and just call the groups on the bottom the “lanthanides” and “actinides.”
transition metals
elements in groups 3-12, and the two groups at the bottom of the periodic table
random facts about various transition metals
Some transition metals can form ions with more than one charge. Iron, for example, can form both the Fe+2 and Fe+3 ions, depending on what you do to it.
Iron, nickel, and cobalt are all magnetic.
Steel is mostly iron, with a little bit of carbon and other elements added to make it stronger and more corrosion resistant.
Transition metals are used to make practically everything.
lanthanides and actinides
The lanthanides and actinides are given these names because one of the rows starts with lanthanum and the other starts with actinium.
The lanthanides are used in optical coatings (such as shiny sunglasses and other lenses) while the actinides are used in nuclear power plants, atomic bombs, and smoke detectors.
