breaking chemical bonds release energy review
In chemistry, the chemical bond is the force, keeping the atoms together in molecules or crystals. The formation of chemical bonds between elements to form molecules is systematized into chemical bonding theories.
Chemistry and the concept of oxidation are used to predict the structure and molecular composition.
Classical physics of electrical bonding and the concept of negative electrodes are used to predict many ionic structures. With more complex compounds, such as metallic complexes, inexplicable chemistry and more perfect explanations based on the foundations of quantum mechanics.
Chemical processes are always accompanied by energy changes. The energy that can be released, can be absorbed in different forms: heat, electricity or photovoltaics. All chemical bonds are in the following chemical bonds :
1. Ion bond
Ion bond is a chemical bond that is essentially an electrostatic attraction between two charged-negative ions. Ion bonding is usually a bond between non-metallic atoms and metal atoms.
Atoms of metal (with 1, 2, 3 electrons outermost layer) have a small electromagnetic, easy to lose electrons create cation (positive). Non-metallic atoms (with 5, 6, 7 electrons in the outermost layer) have a high electronegativity, which is readily accepting electrons to produce anions.
The ionic bond is formed by the electrostatic attraction between typical and nonmetal metals.
2. Covalent bond:
Covalent bond is a bond formed between atoms by one or more common electron pairs. As the formation of the H2 molecule, H atom has an electron configuration of 1s2. Each atom of H contributes one electron to form a pair of electrons in the H2 molecule.
Thus, in the H2 molecule, each atom has two, the stable species of helium-rare gas. Covalent bonds are divided into two types: nonpolar covalent bonds and polarizable bonds
3. Coherent covalent bond:
Coherent covalent bonding (also known as bonding for cation) is a special type of covalent bond, in which the electrons share only one unique atom. When the link is formed, its strength is no different than the covalent bond.
4. Metal bond:
Metal bond is the inner link of the metal. It is the sharing of free electrons between metal atoms in the crystal lattice.
From a traditional point of view, the metal bond is nonpolar, in which either no electronegativity difference (for elemental metals) or very small (for alloys) involved in bonding interactions, and the electrons involved in this interaction are free in the lattice structure of the metal.
5. Hydrogen bonding:
Hydrogen bonding is a chemical bonding when there is an electrostatic attraction between: H is a hydrogen atom associated with strong electronegative elements such as N, Cl, O, F The element has a strong electronegative, negative electricity.
What is the energy released or absorbed in a chemical reaction?
The energy released or absorbed in a chemical reaction is called the thermal effect of the reaction. Why this reaction alters energy, other reactions absorb energy?
A chemical reaction is the creation of a new substance from the original substance with the breaking of the chemical bond in the reactant and the formation of new bonds in the product of the reaction.
Breaking the bonds must consume energy, creating new bonds that emit energy. The energy needed to break a chemical bond is called the binding energy. If the bonds in the reactants are less stable than the new ones formed in the product, the reaction will emit energy.
In contrast, if the bond in the reactant is more stable in the constituent, the energy-absorbing reaction.
The breaking of chemical bonds never releases energy to the external environment. Energy is only released when chemical bonds are formed. In general, a chemical reaction involves two steps:
Step 1: The original chemical bonds between the atoms are broken,
Step 2: New bonds are formed.
These two steps are sometimes lumped into one event for simplicity, but they are really two separate events. For instance, when you burn methane (natural gas) in your stove, the methane is reacting with oxygen to form carbon dioxide and water. Chemists often write this as:
CH4 + 2 O2 → CO2 + 2 H2O + energy
This balanced chemical equation summarizes the chemical reaction involved in burning methane. The reactants are on the left, the products are on the right, and the arrow represents the moment the reaction happens. But there are a lot of interesting things happening that are hidden behind that arrow. A more detailed equation would look something like this:
CH4 + 2 O2 + a little energy → C + 4 H + 4 O → CO2 + 2 H2O + lots of energy