Atoms are tiny particles that make up the universe, while molecules are made from atoms (even a single atom). However, both constitute small, identifiable units.Continue Reading
Atoms are what make up everything from pencils to humans to the ocean. At one time, scientists thought they were the smallest possible particle and that they were indivisible; however, they can be divided. Each atom has a nucleus made of protons and neutrons surrounded by orbiting electrons. Protons are positively charged, and electrons are negatively charged. Neutrons are neutral. All three of these particles can be divided up into smaller particles called quarks. The number of protons, neutrons and electrons an atom has determines what element it is. For instance, sodium has 11 protons, 11 electrons, and 12 neutrons.
A molecule, on the other hand, is indivisible in its own way: by definition, it is the smallest particle of a substance that still retains the properties of that substance. Therefore, although it can be divided into smaller parts (atoms and so on), it does make a unit. Single atoms can make up a molecule, such as the noble gases.
Most molecules are formed when atoms bond in a particular way. For instance, the chemical formula for water is H20, meaning that two hydrogen atoms bond with one oxygen atom. One set of this compound, exactly two hydrogen atoms and one oxygen atom, makes a molecule. If it were divided again, it would be hydrogen and oxygen atoms, not water.Learn more about Atoms & Molecules
In a molecule of sodium chloride, which has the chemical formula NaCl, there are two atoms: one atom each of sodium and chloride. Sodium chloride is an ionic compound formed by the reaction of the metal sodium and the nonmetal chlorine.Full Answer >
A polar molecule is characterized by the uneven distribution of the electrons that form the covalent bonds between each atom in the molecule, resulting in a slightly positively charged side and a slightly negatively charged side. This occurs because of the differences in electronegativity between atoms of different elements.Full Answer >
The distance of each oxygen atom from the central carbon atom in a molecule of carbon dioxide CO2 is 1.1621 angstroms, according to the National Institute of Standards and Technology's Computational Chemistry Comparison and Benchmark Database. Angstroms are commonly used in measurements of extremely small lengths.Full Answer >
The Lewis structure for SeO2, known as selenium dioxide, is one atom of selenium doubly bonded to a molecule of oxygen on each side, resulting in a total of two atoms of oxygen. Selenium's electrons are a completed pair, and the molecule does not have any lone pairs of electrons. The oxygen molecules bonded to selenium each have two lone pairs of electrons.Full Answer >