| A | B |
|---|
| atomic number | The number of protons in the nucleus of an atom |
| covalent bond | A sharing of one or more electrons between atoms or a group of atoms |
| electron | A negatively charged unit of matter that occupies one of the orbitals around the atomic nucleus |
| ion | Charged particles resulting from a gain or loss of electrons |
| ionic bond | A transfer of electrons resulting in ions of opposite charge attracting each other and staying together |
| isotope | An element with the same number of protons but a different number of neutrons |
| mass number | The total number of protons and neutrons in an atoms nucleus |
| neutron | A unit of matter, one or more of which occupies the atomic nucleus and with no electric charge |
| proton | Positively charged particle, one or more of which resides in the nucleus of each type of atom |
| ionic bond | A chemical bond resulting from a transfer of electrons and the resulting attraction of the positively and negatively charged ions |
| covalent bond | A chemical bond resulting from the sharing of electrons |
| molecule | A union of atoms held together by covalent bonds |
| compound | A substance formed from ionic bonds |
| carbon | The backbone of all organic molecules. It can form up to four strong covalent bonds, allowing it to build complex structures such as chains, rings, and branches in carbohydrates, lipids, proteins, and nucleic acids. |
| hydrogen | The most abundant element in the universe. In living systems, it bonds with carbon and oxygen to form essential molecules like water and organic compounds. It also helps store and release energy during chemical reactions |
| nitrogen | A key part of amino acids (the building blocks of proteins) and nucleotides (the building blocks of DNA and RNA). It is essential for growth, repair, and heredity in all living things. |
| phosphorus | A component of nucleic acids (DNA and RNA) and energy molecules like ATP. |
| sulfer | Important for maintaining shapes/provides rigidity to amino acids, polypeptide chains, & proteins |
| oxygen | Vital for cellular respiration, the process that releases energy from food. It is also part of water and many organic molecules, making it essential for structure and metabolism in living organisms. |
