How does Charle's law relate to breathing? What is the ideal gas law constant? How do you calculate the ideal gas law constant? How do you find density in the ideal gas law? Does ideal gas law apply to liquids? Impact of this question views around the world. You can reuse this answer Creative Commons License. Click here to check your answer to Practice Problem 1. Atoms can combine to achieve an octet of valence electrons by sharing electrons. Two fluorine atoms, for example, can form a stable F 2 molecule in which each atom has an octet of valence electrons by sharing a pair of electrons.
A pair of oxygen atoms can form an O 2 molecule in which each atom has a total of eight valence electrons by sharing two pairs of electrons. The term covalent bond is used to describe the bonds in compounds that result from the sharing of one or more pairs of electrons. To understand how sharing a pair of electrons can hold atoms together, let's look at the simplest covalent bond the bond that forms when two isolated hydrogen atoms come together to form an H 2 molecule.
An isolated hydrogen atom contains one proton and one electron held together by the force of attraction between oppositely charged particles.
The magnitude of this force is equal to the product of the charge on the electron q e times the charge on the proton q p divided by the square of the distance between these particles r 2. When a pair of isolated hydrogen atoms are brought together, two new forces of attraction appear because of the attraction between the electron on one atom and the proton on the other.
But two forces of repulsion are also created because the two negatively charged electrons repel each other, as do the two positively charged protons. It might seem that the two new repulsive forces would balance the two new attractive forces. If this happened, the H 2 molecule would be no more stable than a pair of isolated hydrogen atoms. But there are ways in which the forces of repulsion can be minimized. As we have seen, electrons behave as if they were tops spinning on an axis.
When electrons are paired so that they have opposite spins, the force of repulsion between these electrons is minimized. The force of repulsion between the protons can be minimized by placing the pair of electrons between the two nuclei. The distance between the electron on one atom and the nucleus of the other is now smaller than the distance between the two nuclei.
As a result, the force of attraction between each electron and the nucleus of the other atom is larger than the force of repulsion between the two nuclei, as long as the nuclei are not brought too close together. The net result of pairing the electrons and placing them between the two nuclei is a system that is more stable than a pair of isolated atoms if the nuclei are close enough together to share the pair of electrons, but not so close that repulsion between the nuclei becomes too large.
The hydrogen atoms in an H 2 molecule are therefore held together or bonded by the sharing of a pair of electrons and this bond is the strongest when the distance between the two nuclei is about 0. There is a significant difference between the physical properties of NaCl and Cl 2 , as shown in the table below, which results from the difference between the ionic bonds in NaCl and the covalent bonds in Cl 2. Removing an ion from this compound therefore involves breaking at least six bonds.
Some of these bonds would have to be broken to melt NaCl, and they would all have to be broken to boil this compound. As a result, ionic compounds such as NaCl tend to have high melting points and boiling points. Ionic compounds are therefore solids at room temperature. Cl 2 consists of molecules in which one atom is tightly bound to another, as shown in the figure above. The covalent bonds within these molecules are at least as strong as an ionic bond, but we don't have to break these covalent bonds to separate one Cl 2 molecule from another.
As a result, it is much easier to melt Cl 2 to form a liquid or boil it to form a gas, and Cl 2 is a gas at room temperature. The difference between ionic and covalent bonds also explains why aqueous solutions of ionic compounds conduct electricity, while aqueous solutions of covalent compounds do not.
When a salt dissolves in water, the ions are released into solution. These ions can flow through the solution, producing an electric current that completes the circuit. The resulting molecule is carbon dioxide, or CO2. Steve Brunolli specializes in the areas of personal finance, history and health. How to Calculate the Charge of an Ion.
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How to Calculate Valency. What is an Ionic Compound?
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