An acid is a substance that, when dissolved in water, releases positively charged hydrogen ions (H+). Acids often taste sour, can turn blue litmus paper red, and have a pH value less than 7 on the pH scale. They are known for their ability to react with and neutralize bases, forming water and salts in the process.
A base is a substance that, when dissolved in water, releases negatively charged hydroxide ions (OH-). Bases typically taste bitter, feel slippery to the touch, and have a pH value greater than 7 on the pH scale. They are known for their ability to react with and neutralize acids, forming water and salts in the process.
A hydrocarbon is a chemical compound made up of only two elements: hydrogen (H) and carbon (C). Hydrocarbons are the building blocks of organic chemistry and can exist in various forms, including simple molecules like methane (CH4), ethane (C2H6), and more complex ones like gasoline and plastics. They are essential components of fossil fuels and are known for their role as energy sources.
A mole is a unit of measurement used in chemistry to count and quantify a large number of atoms, molecules, or particles. One mole contains approximately 6.022 x 10^23 entities, a number known as Avogadro's number. This makes it a convenient way to work with extremely small or large quantities of substances in chemical reactions and calculations.
An ionic bond is a type of chemical bond formed between two atoms when one atom donates electrons (becomes positively charged) and the other atom accepts those electrons (becomes negatively charged). This transfer of electrons results in the formation of oppositely charged ions, typically a positively charged cation and a negatively charged anion. These ions are attracted to each other due to their opposite charges, creating a strong electrostatic force that holds them together in a stable compound.
A covalent bond is a chemical bond formed between two atoms share electrons. In a covalent bond, both atoms contribute electrons to create a shared electron pair. This sharing of electrons results in a strong attraction that holds the atoms together in a molecule, allowing them to achieve a stable electron configuration.
A Lewis structure, also known as a Lewis dot structure or electron dot structure, is a diagram or representation used to show the arrangement of valence electrons (the outermost electrons) in an atom or molecule. It uses dots or other symbols to represent electrons, allowing us to visualize how atoms are connected and how electrons are shared or transferred in chemical compounds.
Organic chemistry is a branch of chemistry that focuses on the study of compounds primarily composed of carbon and hydrogen atoms, often with oxygen, nitrogen, sulfur, and other elements as well. It is the branch of chemistry that deals with the structure, properties, reactions, and synthesis of organic compounds, including those found in living organisms.
Inorganic chemistry is a branch of chemistry that focuses on the study of compounds that do not primarily contain carbon-hydrogen (C-H) bonds. It deals with the properties, structure, and reactions of a wide range of chemical compounds, including minerals, metals, and non-metallic substances, but excludes organic compounds that primarily consist of carbon and hydrogen atoms.
A hydrogen bond is a type of chemical bond that occurs when a hydrogen atom, already covalently bonded to one atom (usually nitrogen, oxygen, or fluorine), is attracted to another nearby atom with a partial negative charge. This attraction creates a relatively weak electrostatic bond between the hydrogen atom and the second atom, leading to unique properties in substances where hydrogen bonds are present.
Periodicity in chemistry refers to the recurring and predictable patterns or trends in the properties of elements found in the periodic table. These patterns are based on the element's atomic number, which determines its electron configuration and influences its chemical behavior and physical properties.
Avogadro's number, denoted as NA, is a fundamental constant representing the number of atoms, ions, or molecules in one mole of a substance. It is approximately 6.022 x 10^23 entities per mole and serves as a bridge between the atomic and macroscopic scales, allowing chemists to count and work with extremely large numbers of particles in chemical reactions and calculations.