write about covalent compounds
Answers
Explanation:
Covalent bonds form when two or more nonmetals combine. For example, both hydrogen and oxygen are nonmetals, and when they combine to make water, they do so by forming covalent bonds. Compounds that are composed of only non-metals or semi-metals with non-metals will display covalent bonding and will be classified as molecular compounds.
As a general rule of thumb, compounds that involve a metal binding with either a non-metal or a semi-metal will display ionic bonding. Thus, the compound formed from sodium and chlorine will be ionic (a metal and a non-metal). Nitrogen monoxide (NO) will be a covalently bound molecule (two non-metals), silicon dioxide (SiO2) will be a covalently bound molecule (a semi-metal and a non-metal) and MgCl2 will be ionic (a metal and a non-metal).
A polyatomic ion is an ion composed of two or more atoms that have a charge as a group (poly = many). The ammonium ion (see figure below) consists of one nitrogen atom and four hydrogen atoms. Together, they comprise a single ion with a 1+ charge and a formula of NH4+. The carbonate ion (see figure below) consists of one carbon atom and three oxygen atoms and carries an overall charge of 2−. The formula of the carbonate ion is CO32−.
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The atoms of a polyatomic ion are tightly bonded together and so the entire ion behaves as a single unit. Several examples are found in Table 3.3.1. Nonmetal atoms in polyatomic ions are joined by covalent bonds, but the ion as a whole participates in ionic bonding. For example, ammonium chloride (NH4Cl) has ionic bonding between a polyatomic ion, NH+4NH4+ , and Cl−Cl− ions, but within the ammonium ion (NH4+), the nitrogen and hydrogen atoms are connected by covalent bonds (shown above).
Both ionic and covalent bonding are also found in calcium carbonate. Calcium carbonate (CaCO3) has ionic bonding between calcium ion Ca2+Ca2+ and a polyatomic ion, CO2−3CO32− , but within the carbonate ion (CO32-), the carbon and oxygen atoms are connected by covalent bonds (shown above).
Characteristics of Covalent (Molecular) Compounds
Compounds that contain covalent bonds (also called molecular compounds) exhibit different physical properties than ionic compounds. Because the attraction between molecules, which are electrically neutral, is weaker than that between electrically charged ions, covalent compounds generally have much lower melting and boiling points than ionic compounds For example, water (molecular compound) boils at 100 °C while sodium chloride (ionic compound) boils at 1413 °C. In fact, many covalent compounds are liquids or gases at room temperature, and, in their solid states, they are typically much softer than ionic solids. Furthermore, whereas ionic compounds are good conductors of electricity when dissolved in water, most covalent compounds, being electrically neutral, are poor conductors of electricity in any state. The attraction between molecules (called intermolecular forces)
Answered by
professor P.A.Ryan Ahmed
From IIT kota
Answer:
Covalent compounds generally have low boiling and melting points, and are found in all three physical states at room temperature. Covalent compounds do not conduct electricity; this is because covalent compounds do not have charged particles capable of transporting electrons.