Answer:
Identifying whether or not an element is an ion is a very simple process. Identify the charge of the element. ... The number of electrons is equal to the atomic number minus the charge of the atom. Refer to an element with either a positive or negative charge as an ion.
La radiación alfa consiste en núcleos de helio-4 (4He) y es detenida fácilmente por una hoja de papel. La radiación beta, que consiste en electrones, es detenida por una placa de aluminio. La radiación gamma es finalmente absorbida cuando penetra en un material denso.
Answer:
Fossils are the some traces or portions of the animals or plants, buried and preserved from past in rocks, sediments or ice.
Explanation:
Correct match is as follows-
- Mold and cast fossils- An organism is buried in sediment after it dies.The hard part of organism leave behind a empty space imprinted in the rock. Later sediments and minerals fill the space and harden to make the original copy of the organisms.
- Carbon film fossils- An organism buried in sediments gets squeezed and heated inside the earth , leaving behind a thin carbon outline of the organism on a rock.
- Amber fossil- An organism covered in tree resin or tree sap , which then hardens with the body of the organisms preserved inside.
- Ice fossil- An organism dies in a cold place on earth , its body becomes frozen and covered in layers of ice . The hard and soft part of the body may be preserved.
Answer:
The concentration of COF₂ at equilibrium is 0.296 M.
Explanation:
To solve this equilibrium problem we use an ICE Table. In this table, we recognize 3 stages: Initial(I), Change(C) and Equilibrium(E). In each row we record the <em>concentrations</em> or <em>changes in concentration</em> in that stage. For this reaction:
2 COF₂(g) ⇌ CO₂(g) + CF₄(g)
I 2.00 0 0
C -2x +x +x
E 2.00 - 2x x x
Then, we replace these equilibrium concentrations in the Kc expression, and solve for "x".
![Kc=8.30=\frac{[CO_{2}] \times [CF_{4}] }{[COF_{2}]^{2} } =\frac{x^{2} }{(2.00-2x)^{2} } \\8.30=(\frac{x}{2.00-2x} )^{2} \\\sqrt{8.30} =\frac{x}{2.00-2x}\\5.76-5.76x=x\\x=0.852](https://tex.z-dn.net/?f=Kc%3D8.30%3D%5Cfrac%7B%5BCO_%7B2%7D%5D%20%5Ctimes%20%5BCF_%7B4%7D%5D%20%7D%7B%5BCOF_%7B2%7D%5D%5E%7B2%7D%20%7D%20%3D%5Cfrac%7Bx%5E%7B2%7D%20%7D%7B%282.00-2x%29%5E%7B2%7D%20%7D%20%5C%5C8.30%3D%28%5Cfrac%7Bx%7D%7B2.00-2x%7D%20%29%5E%7B2%7D%20%5C%5C%5Csqrt%7B8.30%7D%20%3D%5Cfrac%7Bx%7D%7B2.00-2x%7D%5C%5C5.76-5.76x%3Dx%5C%5Cx%3D0.852)
The concentration of COF₂ at equilibrium is 2.00 -2x = 2.00 - 2 × 0.852 = 0.296 M