Atoms, Molecules, & Compounds
Wikipedia
Introduction to Scientific Processes
All living organisms are made up of matter and all matter is made up of elements. Oxygen, carbon, hydrogen, and nitrogen are the four elements that account for 96% of all living organisms, with calcium, phosphorus, sulfur, sodium, chlorine, and magnesium accounting for the remaining 3.7%.
Different elements can combine to form compounds such as water, which is fundamental to life. matter can exist in different states as a solid, liquid, or gas.
The smallest unit of an element is an atom, which is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Individual atoms can be held together by chemical bonds to form molecules and ionic compounds. Common types of chemical bonds include ionic bonds, covalent bonds, and hydrogen bonds.
Ionic bonding involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds.
Ions are atoms (or groups of atoms) with an electrostatic charge. Atoms that gain electrons make negatively charged ions (called anions) whereas those that lose electrons make positively charged ions (called cations).
Unlike ionic bonds, a covalent bond involves the sharing of electron pairs between atoms. These electron pairs and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
A hydrogen bond is primarily an electrostatic force of attraction between a hydrogen atom which is covalently bound to a more electronegative atom or group such as Oxygen. A ubiquitous example of a hydrogen bond is found between water molecules.
Different elements can combine to form compounds such as water, which is fundamental to life. matter can exist in different states as a solid, liquid, or gas.
The smallest unit of an element is an atom, which is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Individual atoms can be held together by chemical bonds to form molecules and ionic compounds. Common types of chemical bonds include ionic bonds, covalent bonds, and hydrogen bonds.
Ionic bonding involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds.
Ions are atoms (or groups of atoms) with an electrostatic charge. Atoms that gain electrons make negatively charged ions (called anions) whereas those that lose electrons make positively charged ions (called cations).
Unlike ionic bonds, a covalent bond involves the sharing of electron pairs between atoms. These electron pairs and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
A hydrogen bond is primarily an electrostatic force of attraction between a hydrogen atom which is covalently bound to a more electronegative atom or group such as Oxygen. A ubiquitous example of a hydrogen bond is found between water molecules.