Difference between a Mixture and a Compound
A mixture is a combination of two or more materials which can be separated. When forming a mixture, there is no chemical reaction that takes place and so no new substance is formed. When the constituents of a mixture are combined they can be physically separated (Tillery, Enger & Ross, 2008). A good example is a mixture of sand and iron. When the two elements are mixed they don’t result to a new substance, but instead they form a mixture which can later be separated by use of a magnet. The magnet will pick the iron leaving behind the sand. On the other hand, a compound is formed as a result of bonding between various elements. These elements are in a fixed ratio. When constitutes of a compound are chemically combined they result into a new substance. The constituents of a compound are normally divided into their core elements by chemical means. This chemical separation method involves several procedures.
Difference between a Compound and an Element
A combination of various atoms from different substances results to the formation of a compound. For example, Carbon dioxide consists of Carbon ions and Oxygen ions which are held together by electrical attraction. In contrast, an element is made up of same type of atom (Tillery, Enger & Ross, 2008). For example, Oxygen has one molecule so it exits independently. A compound can be broken down into simpler substances through chemical reactions while elements cannot be broken down thus one can be able to identify whether a substance is a compound or an element through chemical reactions. For instance, Carbon monoxide, which is a compound, can be broken down through a chemical reaction to form Carbon and Oxygen atoms while Oxygen, which is an element, cannot be broken into simpler substances. Also, one can identify whether a substance is a compound or an element by looking at the periodic table. In the periodic table, elements have only one capital letter for example, Calcium which is written as Ca. A substance can be identified as a compound or an element by looking at the equation. If the equation has more than one capital letters, then it is a compound, but if there is only one capital letter, it is an element (Tillery, Enger & Ross, 2008).
Difference between Ionic and Covalent Bond
Ionic bond is a bond formed between a non metal and a metal while a covalent bond is a bond formed between two non metals. Ionic bond is formed when the sharing of electron is imbalanced thus the electron from atom X is completely lost to atom Y whereas the covalent bond is formed when the two atoms are able to share the electrons equally. Ionic bonding involves electrostatic attraction between oppositely charged ions in a chemical compound while covalent bond is characterized by the sharing of pairs of electrons between atoms (Stoker, 2012). Covalent bond has a definite shape while ionic bond had no definite shape.
According to Stoker (2012), Ionic bonds have higher melting and boiling points compared to covalent bonds this is because in ionic bonds more energy is required to break all the ionic bonds between the atoms for it to melt while in covalent bonds only little amount of energy is required to break the bonds thus a low melting point and boiling point. For example, when you want to break the bond between Sodium Chloride which has an ionic bond it means that you have to use a lot of energy to break the same bonds to melt Sodium Chloride and the breaking of all bonds will boil the Sodium Chloride. Consequently, ionic compounds have high melting points and boiling points. The electronegativity of atoms results the formation of the covalent bonds. Electronegativity entails atoms ability to attract electrons. Formation of covalent bond is as a result atoms ability to attract electrons. If the power between the two atoms is the same they share the electrons and form a covalent bond, but if one atom’s power exceeds the other, then one loses the electron or electrons to the other forming an ionic bond (Stoker, 2012). Compounds with ionic bonds are solid at room temperature while those with covalent bond are in liquid or gaseous form at room temperature.
Formation of Ionic Compounds
When metals from the left side of the periodic table reacts with the nonmetals from the right side of the periodic table an ionic compound is formed because the metal and the nonmetal will contribute electrons to form a pair or pairs of electrons which will not be shared by the two atoms rather it will go to the stronger atom. This is a result of one atom having a strong affinity to attract electrons than its counterpart electrons (Zumdahl, 2009). The nonmetals on the right side of the periodic table have seven valence electrons on their outer orbit while the metals on the left side of the periodic table have one valence electron in their outer orbit thus; the nonmetals on the right side of the periodic table have high electron- negativity. This means that these nonmetals have more power to attract electrons to them. Therefore, the nonmetals on the right side of the periodic table can easily attract the one valence electron from the metals on the left side of the periodic table. At the end, they form an ionic compound and share each other’s electrons (Tillery, Enger & Ross, 2008). Examples of such ionic compounds are Sodium Chloride (NaCl) and Magnesium Chloride (Mg2Cl3).
Formation of Covalent Bonds
Most of nonmetals on the right side of periodic table have seven valence electrons on their outer orbit (Pace, 2001). Covalent bond is formed when nonmetals from the right side of the periodic table bond with each other because those metals have seven valence electrons on their outer obit thus they just need one electron to be stable. Each atom shares one of its outermost electron thus two electrons are shared between the atoms. In this case, there is attraction between the positively charged atom and shared electrons.
The presence of shared electrons at the edges of two atoms results to the formation of a covalent bond. In this type of bonding none of the atoms loses or gains electrons. Compounds with covalent bonds include Hydrogen Chloride (HCl) and Methane (CH4). Carbon dioxide has a covalent bond between Hydrogen ion and Chlorine ion while Methane has a covalent bond between Carbon ion and Hydrogen ion. The covalent bond formed between these atoms is easy to break since distinct molecules are formed. Thus, this makes the melting and boiling point of covalent bonded compounds low.
References
Pace, N. R. (2001). The universal nature of biochemistry [Special feature]. Proceedings of the National Academic of Sciences, 98, 805 – 808.
Stoker, H. S. (2012). General, Organic, and Biological Chemistry. New York: Cengage Learning.
Tillery, B. W., Enger, E. E., & Ross, F. C. (2008). SCI110: Integrated science. New York, NY: McGraw-Hill.
Zumdahl, S. S. (2009). Chemical Principles. New York: Cengage Learning.