Answer:
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- <em>19. C₂H₂, HF, and H₂O₂ are molecular compounds</em>
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- <em>20. The formula is CuSO₄. 5H₂O</em>
Explanation:
<u><em>Question 19.</em></u>
The three the chemical formulae in red, C₂H₂, HF, and H₂O₂, represent compounds because a compound is the chemical union of two or more atoms of different kind.
The chemical union is done either by ionic bonds or covalent bonds.
C, H, F, and O are all non-metal elements. Non-metals combine each other through covalent bonds, which is the bond in which electrons are shared to complete the valence shell. Ionic bonds are formed by the electrostatic atraction between ions of different charge and is typical of the bond between a metal and a non-metal.
Thus, all the bonds are covalent and the compounds are molecular compounds.
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<u><em>Question 20. </em></u>
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You can determine the chemical formula using the molar masses of both Copper(II) sulfate and water.
- Molar mass of copper(II) sulfate: 159.609 g/mol
- Molar mass of water: 18.015 g/mol
Call n the number of water molecules in the molecular formula:
The ratio of water to copper(II) sulfate is:
- n × molar mass of water / molar mass of the compound
- n × 18.015 / (n × 18.015 + 159.609) = 36%
- 18.015n = 0.36(18.015n + 159.609)
- 18.015n = 6.4854n + 57.45924
Therefore, the formula of the hydrate contains 5 molecules of water and it is CuSO₄.5H₂O.
Answer:
Saffi only
Explanation:
I just took the test and that was the correct answer :)
Sudden slip on a fault. Stresses in the earth's outer layer push the sides of the fault together. Stress builds up and the rocks slip suddenly, releasing energy in waves that travel through the earth's crust and cause the shaking that we feel during an earthquake.
Faults are caused by the tectonic plates grinding and scraping against each other as they continuously and slowly move. In California, for example, there are two plates - the Pacific Plate (which extends from western California to Japan, including much of the Pacific Ocean floor) and the North American Plate (which is most of the North American continent and parts of the Atlantic Ocean). The Pacific Plate moves northwestward past the North American Plate along the San Andreas Fault at a rate of about two inches per year.
Parts of the San Andreas Fault system adapt to this movement by constant "creep" resulting in many tiny shocks and a few moderate earth tremors. In other parts, strain can build up for hundreds of years, producing great earthquakes when it finally releases. Large and small earthquakes can also occur on faults not previously recognized; recent earthquakes in Alabama and Virginia are good examples.
FICTION: “Mega Quakes” can really happen.
The magnitude of an earthquake is related to the area of the fault on which it occurs - the larger the fault area, the larger the earthquake. The San Andreas Fault is 800 miles long and only about 10-12 miles deep, so that earthquakes larger than magnitude 8.3 are extremely unlikely.
The largest earthquake ever recorded by seismic instruments anywhere on the earth was a magnitude 9.5 earthquake in Chile on May 22, 1960. That earthquake occurred on a fault that is almost 1,000 miles long and 150 miles wide, dipping into the earth at a shallow angle. The magnitude scale is open-ended, meaning that scientists have not put a limit on how large an earthquake could be, but there is a limit just from the size of the earth. A magnitude 12 earthquake would require
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Explanation:
Electronic Configuration for Li: 1s²2s¹
Electronic Configuration for Cl: [Ne]3s²3p⁵
When Lithium and Chlorine bonds together, the electron in the Lithium 2s subshell will be transfered to the Chlorine 3p subshell, giving both the Lithium and Chlorine atoms a complete 1st and 3rd energy levels respectively.
Formula for Lithium chloride: LiCl.