Answer:
18
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas.
Explanation:
hope the answer was helpful......
Answer:
The theory of Oparin and Haldane was based on the fact that the primitive atmosphere was very different from the current atmosphere, since energy was abundant on the young planet. Both proposed that the appearance of life was preceded by a period they called "chemical evolution."
On the other hand, Miller Urey made an experiment where it was shown that some organic components were formed spontaneously if they were simulating the conditions of the Earth's early atmosphere.
Explanation:
The first hypotheses about the origin of life on Earth were suggested by Oparin and Haldane, who worked independently. Oparin presented his ideas on the origin of life in the year of 1922 by publishing them in the year of 1924. For his part, Haldane published similar ideas in 1929, however, Haldane gave priority to Oparin in the formulation of the theory.
Oparin based his hypotheses using a model he called "coacervates", which are colloidal systems formed by macromolecules that formed in aqueous media and would have evolved to form cells with membranes. According to Oparin, living beings modified the primitive atmosphere and this would have prevented, the formation of life from inorganic substances.
The Miller and Urey experiments helped reinforce the theory that the first way of life was created spontaneously through chemical reactions. However, there are still many scientists who are not convinced.
Answer: 
for the reaction 
is -108kJ
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
![\Delta H=[n\times B.E_{reactants}]-[n\times B.E{products}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20B.E_%7Breactants%7D%5D-%5Bn%5Ctimes%20B.E%7Bproducts%7D%5D)
where, n = number of moles
Now put all the given values in this expression, we get
![\Delta H=[1\times B.E_{Cl_2}+1\times B.E_{F_2}]-[2\times B.E_{ClF}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B1%5Ctimes%20B.E_%7BCl_2%7D%2B1%5Ctimes%20B.E_%7BF_2%7D%5D-%5B2%5Ctimes%20B.E_%7BClF%7D%5D)
![\Delta H=[(1\times 243)+(1\times 159)]-[2\times 255]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%281%5Ctimes%20243%29%2B%281%5Ctimes%20159%29%5D-%5B2%5Ctimes%20255%5D)
Thus for the reaction is -108kJ
Materials are transferred between individual cells and their internal environment through the cell membrane by diffusion, osmosis, and active transport. During diffusion and osmosis, molecules move from a higher concentration to a lower concentration. Osmosis: Osmosis is the movement of solvent particles across a semipermeable membrane from a dilute solution into a concentrated solution. Diffusion: Diffusion is the movement of particles from an area of higher concentration to lower concentration. This would be the diffusion.
If two nonmetals are bonded together. So look at your periodic table of elements and decide if the two elements that are being bonded are nonmetals or not.
