Basic chemistry involves the study of matter that is composed of atoms. Each atom comprises a nucleus (which contains protons and neutrons) and electrons.
Electrons occupy regions called orbitals around the nucleus, and they determine the properties of an atom. Chemical reactions involve sharing or exchanging these electrons.
Atoms
Atoms are the basic building blocks of all matter. They are made up of protons and neutrons, and electrons. The protons and neutrons are found in a tiny nucleus at the center of an atom, while the electrons are whizzing around the outer region of the atom. The attraction between the protons and the electrons holds the atom together.
In some atoms, the protons and electrons cancel out, leaving a neutral particle with no net charge. Hydrogen (H) is a perfect example of this. Electrons in atoms are arranged into shells, each filled with electrons at different energy levels. The outermost shell, called the valence shell, is usually filled with the most electrons. This is the most energetically stable shell of an atom, and therefore it is the most likely to form chemical bonds with other atoms to form molecules.
Molecules
Molecules are the minor units of a substance that retain all of the composition and chemical properties of the original meaning. They are formed when atoms bond with each other to form multiatom combinations.
Each atom comprises protons (positively charged), electrons, and neutrons. The atom’s nucleus contains protons and neutrons, while the outer parts of the bit have electrons.
A molecule can be homonuclear, meaning it consists of one element, such as oxygen, or heteronuclear, containing two or more details, such as water. Heteronuclear molecules are often bonded with other atoms of the same element, such as carbon dioxide or carbon monoxide.
A molecule is named based on its formula. The formula is usually a line of chemical element symbols, numbers, and sometimes also other symbols.
Compounds
A compound is a pure chemical substance that consists of two or more different chemical elements held together in a fixed ratio through a defined spatial arrangement. They can be salts, ionic compounds, inter-metallic compounds, or complexes.
Some common examples of compounds include water, carbon dioxide, and table salt. All these substances have a fixed ratio of atoms arranged through chemical bonds.
Compounds are an essential component of all Basic chemistry. They are used to identify and study various chemical reactions.
When naming a compound, the element symbol is usually placed first if two elements don’t share a metal atom. If there are more than two nonmetal elements, the metal goes first, and a roman numeral is added after.
The number of atoms in each element is also written as a right-hand subscript, using the Hill system, with phosphorus being to the left of sulfur. This is called the molecular formula of a compound.
Reactions
Reactions are chemical changes that happen when the molecules in two or more substances interact to form new substances. These new substances are called products.
There are many different reactions. Chemists use these reactions to make valuable new compounds. The most common are synthesis, decomposition, single displacement, double displacement, and combustion. These reactions can be simple when one element displaces another or complex when details are exchanged between reactants to form new compounds.
Reactions are written as a chemical equation, a mathematical statement that symbolizes product formation from reactants while stating certain conditions for the response. The equation is balanced to show that the mass of the reactants on one side exactly equals the group of the products on the other.
