Power Words

More About Power Words

atom: The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and uncharged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

bond: (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.

caffeine: A natural, plant-based stimulant, which activates the nervous system and heart. The leaves, seeds and fruits of many plants contain caffeine. In coffee plants and tea bushes, caffeine acts as a natural pesticide. It will kill or harm insects that attempt to dine on the plant. Caffeine is also toxic to some types of plants, bacteria — even frogs and dogs.

carbohydrates: Any of a large group of compounds occurring in foods and living tissues, including sugars, starch and cellulose. They contain hydrogen and oxygen in the same ratio as water (2:1) and typically can be broken down in an animal’s body to release energy.

carbon: A chemical element that is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules. (in climate studies) The term carbon sometimes will be used almost interchangeably with carbon dioxide to connote the potential impacts that some action, product, policy or process may have on long-term atmospheric warming.

catenation: A term in chemistry for the propensity of an atom to link up — or bond — with others of the same element to form chains. Carbon is very good at this.

chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H₂O.

compound: (often used as a synonym for chemical) A compound is a substance formed when two or more chemical elements unite (bond) in fixed proportions. For example, water is a compound made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H₂O.

crude oil: Petroleum in the form as it comes out of the ground.

crystal: (adj. crystalline) A solid consisting of a symmetrical, ordered, three-dimensional arrangement of atoms or molecules. It’s the organized structure taken by most minerals. Apatite, for example, forms six-sided crystals. The mineral crystals that make up rock are usually too small to be seen with the unaided eye.

diamond: One of the hardest known substances and rarest gems on Earth. Diamonds form deep within the planet when carbon is compressed under incredibly strong pressure.

dissolve: To turn a solid into a liquid and disperse it into that starting liquid. (For instance, sugar or salt crystals, which are solids, will dissolve into water. Now the crystals are gone and the solution is a fully dispersed mix of the liquid form of the sugar or salt in water.)

double bond: A type of bond between two atoms within a molecule. In a single bond, atoms share two electrons. In a double bond, they share four. This bond is slightly less stable than a single bond.

electron: A negatively charged particle, usually found orbiting the outer regions of an atom; also, the carrier of electricity within solids.

element: A building block of some larger structure. (in chemistry) Each of more than one hundred substances for which the smallest unit of each is a single atom. Examples include hydrogen, oxygen, carbon, lithium and uranium.

fertilizer: Nitrogen, phosphorus and other plant nutrients added to soil, water or foliage to boost crop growth or to replenish nutrients that were lost earlier as they were used by plant roots or leaves.

field: An area of study, as in: Her field of research is biology.

fossil fuel: Any fuel — such as coal, petroleum (crude oil) or natural gas — that has developed within the Earth over millions of years from the decayed remains of bacteria, plants or animals.

fullerenes: Molecules of carbon that resemble tiny, soccer ball-like cages or tubes when the chemical bonds between all of the carbon atoms are drawn. Most fullerenes are ball-shaped. Chemists created the first of these in 1985 and nicknamed them “buckyballs” after Buckminster Fuller, the famous architect and engineer who designed dome-shaped structures whose shapes resemble fullerene balls. In 2020, chemists created related all-carbon tubes, now known as fullertubes.

graphene: A superthin, superstrong material made from a single-atom-thick layer of carbon atoms that are linked together.

graphite: Like diamond, graphite (the substance found in pencil lead) is a form of pure carbon. Unlike diamond, graphite is very soft. The main difference between these two forms of carbon is the number and type of chemical bonds between carbon atoms in each substance.

hue: A color or shade of some color.

hydrocarbon: Any of a range of large molecules containing chemically bound carbon and hydrogen atoms. Crude oil, for example, is a naturally occurring mix of many hydrocarbons.

Carbon: Molecule-maker supreme

 

Carbon: Molecule-maker supreme

Three things make carbon special. 

Covalent bonds are those within a molecule where various atoms share an electron. Those tight linkages hold the atoms close to one another. Each carbon atom can form four covalent bonds at once. That’s a lot. And it’s not just that carbon can form four bonds, but rather that it wants to form four bonds.

Carbon’s covalent bonds come in three types: single, double and triple bonds. A double bond is extra-strong and counts as two of carbon’s four desired bonds. A triple bond is stronger still, and counts as three. All these bonds and bond types allow carbon to make many types of molecules. In fact, simply replacing any single bond with a double or triple bond will give you a different molecule.

Carbon atoms tend to link up with other carbon atoms to form chains, sheets and other shapes. Scientists call this ability catenation (Kaa-tuh-NAY-shun). Plastic is the name for a family of organic polymers. Their long carbon chains can either be straight or branch out like trees. Each trunk or branch of these polymers is made from a backbone of catenated carbons. Carbon can link into ring shapes, too. Caffeine, a molecule in coffee, is a compact, two-ring, spider-shaped molecule held together by the catenation of carbon atoms. Carbon atoms even connect to form perfectly spherical 60-carbon balls. These are known as buckyballs.

Hydrocarbons: The basis of fossil fuels

Crude oil and natural gas are fossil fuels made from a complex mix of natural organic chemicals, generally known as hydrocarbons. That term is a mash-up of hydrogen and carbon. These molecules are, too.

The simplest hydrocarbon is methane (METH-ain). It’s made from a single carbon atom bonded (covalently) to four hydrogen atoms. A two-carbon version, ethane (ETH-ain), holds onto six hydrogen atoms. Add a third carbon — and two more hydrogens — and you get propane. Notice that the end of each name stays the same. Only the first part, or prefix, changes. Here, that prefix tells us how many carbons the molecule holds. (Peek at the back of a bottle of hair conditioner. Try to spot some of these prefixes hidden in the long chemical names.)

Once we reach four bound carbons, new hydrocarbon shapes become possible. Since carbon chains can branch, four carbon atoms (and their hydrogens) may bend and connect into unusual shapes. That results in new molecules.

In chemistry, what does it mean to be organic?

 

In chemistry, what does it mean to be organic?

At a minimum, these molecules need carbon. But that’s only the first requirement

t of 118 elements, only one has its own field of study: carbon. Chemists refer to most molecules that contain one or more carbon atoms as organic. The study of these molecules is organic chemistry.

Carbon-based molecules get special attention because no other element comes close to carbon’s versatility. More types of carbon-based molecules exist than all non-carbon ones put together.

Scientists generally define a molecule as organic when it contains not only carbon, but also at least one other element. Typically, that element is hydrogen, oxygen, nitrogen or sulfur. Some definitions say that a molecule must contain both carbon and hydrogen to be organic.

(By the way, in farming, “organic” refers to crops grown without certain pesticides and fertilizers. That use of “organic” is very different from the chemical definitions here.)

Living things are built with organic molecules and operate using organic molecules. Indeed, organic molecules perform the tasks that makes a living thing “alive.” 

DNA, the molecular blueprint for our bodies, is organic. The energy we get from food comes from breaking down carbon-based — organic — molecules. In fact, until the 1800s, chemists thought that only plants, animals and other organisms could make organic molecules. Now we know better. Our oceans created organic molecules before life even existed. Organic molecules can also be made in the lab. Most medicines are organic. So are plastics and most perfumes. Still, organic molecules are seen as a defining feature of life-forms.

But living things also contain lots of molecules that are not organic. Water is a good example. It makes up about six-tenths of our bodyweight but is not organic. We must drink water to live. But drinking water doesn’t satisfy hunger. A hamburger or beans, for instance, contains those organic molecules needed to fuel our bodies’ growth.

In living things, organic molecules usually fall into one of four categories: lipids (such as fats and oils), proteins, nucleic acids (such as DNA and RNA) and carbohydrates (such as sugars and starches). These molecules can get big, though still too small to see with just our eyes. Some may even be organic molecules bonded to other organic molecules. The big ones, made by linking a lot of littler ones, are known as polymers.