Matter is defined as anything that that occupies space and has mass. The mass is the amount of matter an object contains. Mass is a measurement. Matter is composed of basic building blocks called atoms, which are the smallest particle which still holds the chemical properties of an element. Atoms make up elements, and elements can be found in three states of matter, solid, liquid, and gas. When a particle contains one more than one atom, it is defined as a molecule. Molecules which contain more than one element are defined as compounds.
Molecules and compounds require a chemical bond to join atoms. They join together through 3 different types of bonds including covalent, iconic, and hydrogen. When atoms share electrons they have a covalent bond. A water molecule is held together by a covalent bond. When atoms transfer electrons, they have an ionic bond. When this bond occurs one atom will become negatively charged due to a loss, and one will become positively charged due to a gain of electrons. The difference in their charges causes them to attract towards each other forming an ionic bond. Ionic bonds can include NaCl (salt), and because this bond is less strong than a covalent bond, it is more easily dissolvable. The weakest bond of all three is a hydrogen bond. When a hydrogen atom is bonded with an atom through a covalent bond, is bonded to another molecule. In this instance, when different elements form covalent bonds, the electrons may be shared unequally.
H20 is bonded with a hydrogen bond. Two hydrogen atoms shares share their 2 (4 total) electrons with oxygen, making them positively charged but oxygen negatively with 4 remaining unshared electrons. This causes one side to have a more positive charge and one side more negative. When this occurs, it's called a polar molecule. The result of this is shown above, where the more negatively charged O atom is attracted to the positively charged H atom.
Properties of Water
The weak bond in water molecules makes it ideal for supporting life. It has unique properties such as surface tension, capillary action, boiling, freezing, and the ability to be used as a solvent. Cohesion and adhesion are possible due to hydrogen bonding. Water molecules have the ability to 'stick' to themselves and other substances. Surface tension is essential for the pace of evaporation and, even broader, life on Earth. Surface tension wouldn't exist without cohesion, and without surface tension, water would not be able to form droplets. This includes rain droplets to morning dew. Without this attraction, water would evaporate in a matter of milliseconds. There would be no time for absorption or collection.
Capillary action occurs when the attraction of adhesion is greater than cohesion. This allows water to be absorbed and transferred. Capillary action allows water to be distributed by vessels throughout trees, which is essential to life on Earth.
Water's freezing point is 32 degrees fahrenheit and it's boiling point is 212 degrees fahrenheit, and between these two temperatures, is liquid. Life on Earth requires water for many processes, and for most, requires water to be in a liquid state of matter. Most water on Earth is liquid, and because water is joined by hydrogen bonds, it requires a lot of energy to change the temperature of it, let alone the state of matter it's in. This resistance to temperature changes prevents extreme shifts in temperature on Earth. In addition, as water changes states it's density changes as well. As it freezes, the molecules expand, making it less dense. This allows ice to float, and regulates the temperatures in lakes or ponds so life can still live under the surface.
Water is an ideal molecule for a solvent because it is polar. Polar molecules are able to bond easily with other polar molecules. This ability for substances to easily dissolve in water allows many living organisms to store various types and quantities of molecules in their cells.
All macromolecules which are most essential to life (carbohydrates, proteins, nucleic acids, and lipids) are organic compounds. Organic compounds are compounds that are bonded by either carbon-carbon or carbon-hydrogen bonds. Any compound composed of carbon, hydrogen, and oxygen are carbohydrates. A common carbohydrate is glucose (C6H12O6). Glucose is a simple sugar which allows for a quick release of energy. Plants receive their energy from starch, which is a chain of covalently bonded glucose molecules. Not only do plants receive energy from glucose, but the animals that eat plants do as well. They obtain the energy from the cellulose in plants, which is another chain of glucose molecules. Proteins are composed of amino acids. Amino acids are chains of organic molecules containing nitrogen. Protein provides structure, stores energy, allows for internal transportation, and defends against foreign substances. Proteins also make up enzymes which control the speed of chemical reactions. Another type of organic compounds is nucleic acids, which are found in all living cells. When nucleic acids form long chains, they form DNA, which is the genetic materiel containing the code for reproducing and is needed for an organism to pass to its offspring. Proteins are synthesized by the translation of DNA by RNA. The last organic compound is lipids. These do not mix with water and include fats, waxes, and steroids. They make up a significant portion of the membranes surrounding cells.