 |
Chemistry, a branch of physical science, is the study of the composition, properties and behavior of matter. |
1. A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus.
2. A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions.
Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds. Chemical compounds can be molecular compounds held together by covalent bonds, salts held together by ionic bonds, intermetallic compounds held together by metallic bonds, or complexes held together by coordinate covalent bonds.
3. Calculation for chemical substances
mass number = number of neutrons + number of protons
number of protons = atomic number = number of electrons
4. About 25 of the 92 natural element are known to be essential to life. There are four elements of these 25 elements make up approximately 96% of living matter. They are: Oxygen, Hydrogen, Carbon and NITROGEN.
5. A covalent bond is formed when outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms.
6. An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed due to the attraction between an atom that has lost one or more electron (known as a cation) and an atom that has gained one or more electrons (known as an anion). Usually, the cation is a metal atom and the anion is a nonmetal atom.
Sources by:
www.wikipedia.org
Mr. Quick's formative quiz #Basic chemistry
No comments:
Post a Comment