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What happens to atoms when a bond is made?

A chemical bond is formed when atoms are held together by attractive forces. This attraction occurs when electrons are shared between atoms, or when electrons are exchanged between the atoms that are involved in the bond. In other words one atom gains an electron while the other loses an electron.

Why energy is released when bond is formed?

Energy is released when bonds form. Bond formation represents a stable configuration for atoms, sort of like relaxing into a comfy chair. You release all your extra energy when you sink into the chair and it takes more energy to get you back up again.

What happens in an exothermic reaction?

Chemical reactions that release energy are called exothermic. In exothermic reactions, more energy is released when the bonds are formed in the products than is used to break the bonds in the reactants. Exothermic reactions are accompanied by an increase in temperature of the reaction mixture.

How do you know if an equation is exothermic?

In a chemical equation, the location of the word “heat” can be used to quickly determine whether the reaction is endothermic or exothermic. If heat is released as a product of the reaction, the reaction is exothermic. If heat is listed on the side of the reactants, the reaction is endothermic.

Is freezing exothermic?

When water becomes a solid, it releases heat, warming up its surroundings. This makes freezing an exothermic reaction.

Is exothermic positive or negative?

All chemical reactions involve the transfer of energy. Endothermic processes require an input of energy to proceed and are signified by a positive change in enthalpy. Exothermic processes release energy upon completion, and are signified by a negative change in enthalpy.

Is Q positive in endothermic?

When heat is absorbed by the solution, q for the solution has a positive value. When heat is absorbed from the solution q for the solution has a negative value. This means that the reaction absorbs heat fron the solution, the reaction is endothermic, and q for the reaction is positive.

Is work done in an exothermic reaction?

For an exothermic reaction, heat is given off (-q) and w is positive. Negative work means that work is done by the system while postive work means that work is done on the system.

Is a gas expanding exothermic?

Expansion of a gas is an endothermic process. A reaction is a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form, state, or a nuclear reaction. Expansion of a gas is not an endothermic reaction.

Is liquid to gas exothermic?

All phase changes are accompanied by changes in the energy of a system. Changes from a more-ordered state to a less-ordered state (such as a liquid to a gas) are endothermic. Changes from a less-ordered state to a more-ordered state (such as a liquid to a solid) are always exothermic.

What processes are endothermic?

Endothermic Processes

  • Melting ice cubes.
  • Melting solid salts.
  • Evaporating liquid water.
  • Converting frost to water vapor (melting, boiling, and evaporation, in general, are endothermic processes.
  • Making an anhydrous salt from a hydrate.
  • Forming a cation from an atom in the gas phase.
  • Splitting a gas molecule.