Topic

Molecules

Learning resources

Level
High School - College
Format
Book, iPhone/iPad, Mac OS

About Molecules

Molecules are the basic units of matter and the defining structure of materials. The study of molecules and their properties is central to chemistry and materials science. Molecular structure can be represented in a variety of ways, including models, drawings, and equations. The behavior of molecules is determined by their electronic structure, which can be described using quantum mechanics. Molecules can interact with one another to form new materials, and they are essential to the function of living organisms.

In order to learn about molecules, one must first understand atoms. Atoms are the basic units of matter and the defining structure of elements. The term "molecule" refers to the largest particle of an element that can exist in nature and still retain the chemical properties of that element. Molecules are held together by forces called chemical bonds, which are created by the sharing or exchanging of electrons between atoms.

While all atoms are essentially equal, some have more electrons in their outermost shell than others. Electrons are especially attracted to the protons in the nucleus of an atom, and the more electrons an atom has, the more stable it becomes. This is because the more electrons an atom has, the more chances there are for the electrons to occupy the lowest energy levels available.

Atoms can bond with each other in order to create molecules by sharing electrons. When atoms share electrons, they form a chemical bond called a covalent bond. This type of bond results in the electrons being shared equally between the atoms involved. In order for a covalent bond to form, the electrons must be shared between atoms that have similar electronegativities.

Molecules can also be held together by forces called ionic bonds. Ionic bonds occur when one atom donates an electron to another atom. This causes the atoms to become electrically charged, with one atom becoming positive and the other negative. The atoms are then attracted to each other and held together by the electrostatic force.

Ionic bonds are generally stronger than covalent bonds, but they are also less common. Most molecules are held together by covalent bonds. There are, however, some molecules that are held together by ionic bonds. These molecules are called ionic compounds.

Molecules can be either linear or nonlinear. Linear molecules are straight, while nonlinear molecules are bent or twisted. The shapes of molecules are determined by the arrangement of the atoms that make up the molecules. The shapes of molecules also influence the properties of the molecules.

Molecules can be either polar or nonpolar. Polar molecules have a slightly negative charge on one end and a slightly positive charge on the other. Nonpolar molecules do not have a charge. The charges on polar molecules are caused by the uneven distribution of electrons. The charges on nonpolar molecules are caused by the equal distribution of electrons.

Polar molecules are attracted to each other, while nonpolar molecules are not. This is because polar molecules can share electrons, while nonpolar molecules cannot. The charges on polar molecules allow them to form dipole-dipole interactions. These interactions are responsible for the majority of the forces that hold molecules together.

Dipole-dipole interactions are relatively weak, however, and are not strong enough to hold molecules together in the absence of other forces. The other forces that hold molecules together include hydrogen bonds, van der Waals forces, and hydrophobic interactions.

Hydrogen bonds are the strongest of the forces that hold molecules together. They are formed when a hydrogen atom bonded to a highly electronegative atom, such as oxygen or nitrogen, is attracted to another electronegative atom. The hydrogen atom acts as a bridge between the two atoms, and the bond is formed by the sharing of electrons.

Van der Waals forces are relatively weak forces that occur between molecules. They are caused by the temporary imbalance of electrons between molecules. Hydrophobic interactions are also relatively weak forces, but they are responsible for the attraction of nonpolar molecules to each other. These interactions occur when the molecules are in contact with water.

In order to learn about molecules, it is important to understand the forces that hold them together. The forces that hold molecules together determine the shapes of molecules, as well as their properties.

Learning Molecules