The large number of areas covered by the chemical energetics can be explained by the different forms in which chemical energy can be released: heat and combustion work, electrical energy in electrochemistry, radiant energy in chemiluminescent systems.
The chemical energy provided by a reaction reflects the energy balance associated with the electronic modifications suffered by the species involved.
From an energy point of view, a chemical reaction between molecules can be schematized in two stages. The first requires a supply of energy and corresponds to the rupture of the bonds of the reactant molecules with release of the atoms which constitute them.
The second releases energy and concerns the creation, by recombination of these atoms, of new bonds entering the structure of the reaction molecules.
As a general rule, the energy released in the second stage is greater than the first. We are talking about exothermic reaction. The difference between these two energies (reaction enthalpy) measures the amount of chemical energy transferred to the external environment.
It is conceivable that this quantity translates, not only the number, but also the strength of the connections involved.
Answer:
After 6000 years, approximately 500 atoms of carbon-14 will be left in the femur bone of an animal which had 1000 atoms of carbon-14 when the animal died.
Explanation:
The half-life of a radioactive isotope of an element is the time taken for half the atoms present in a given amount of the element to undergo decay or disintegration. For example, the half-life of carbon-14 isotope is 5730 years. This means that, if there are 100 atoms of carbon-14 present in a given sample of a material, in the next 5730 years, approximately, 50 atoms of carbon-14 will be left in the material.
Since the half-life of radioactive isotopes are constant, these radioactive isotopes are used in the determining the ages of ancient life-forms as well as rocks.
In the given example, after 6000 years, approximately 500 atoms of carbon-14 will be left in the femur bone of an animal which had 1000 atoms of carbon-14 when the animal died.
Answer:
H2O2 H2O CO CO2 CH4 are all compounds.
Explanation:
Compounds contains 2 or more ions of different elements in different proportion joined by chemical bonds into a molecule.
The best answer is C
Hope it helped!! :)
