Answer:
D. The atoms are arranged with alternating positive and negative charges. When struck, the lattice shifts putting positives against positives and negatives against negatives.
Explanation:
Metallic crystals takes their properties as a result of metallic bonds in between the atoms.
Metallic bond is actually the attraction between the positive nuclei of all the closely packed atoms in the lattice and the electron cloud jointly formed by all the atoms by losing their outermost shell electrons this is by virtue of their low ionization energy.
Physical properties of metals such as malleability, ductility, electrical conductivity, etc can be accounted for by metallic bonds.
Answer: The correct answer is: the water can transfer heat to your arm more quickly than the air.
Explanation: The heat is transferred from the air or water to your arm through convection. The convective heat transfer coefficient of water is higher than the air's, so, even though the temperature of boiling water is lower, the heat will be transferred more efficiently to the other surface, in this case, the hand.
The absorption spectrum is the result of absorption of light radiation by a material (solid or liquid) as a function of wavelength or frequency. The figure is shown below:
<span>0.127 moles
The formula for nitroglycerin is C3H5N3O9 so let's first calculate the molar mass of it.
Carbon = 12.0107
Nitrogen = 14.0067
Hydrogen = 1.00794
Oxygen = 15.999
C3H5N3O9 = 3 * 12.0107 + 5 * 1.00794 + 3 * 14.0067 + 9 * 15.999 = 227.0829
Now calculate the number of moles of nitroglycerin you have by dividing the mass by the molar mass
2.50 ml * 1.592 g/ml / 227.0829 g/mol = 0.017527 mol
The balanced formula for when nitroglycerin explodes is
4 C3H5N3O9 => 12 CO2 + 10 H2O + O2 + 6 N2
Since all of the products are gasses at the time of the explosion, there is a total of 29 moles of gas produced for every 4 moles of nitroglycerin
Now multiply the number of moles of nitroglycerin by 29/4
0.017527 mol * 29/4 = 0.12707075 moles
Round to 3 significant figures, giving 0.127 moles</span>
Answer:
1. Galvanic oxidation. Example is the corrosion of aluminium wires when in contact with copper wires under wet conditions.
2. Rainwater or Damp/moist air
3. Chromium-plated steel screws or stainless steel screws or galvanized steel screws
Explanation:
1. Galvanic oxidation or corrosion occurs when two different metals with different electrode potentials are brought into contact with each other by means of an electrolyte (usually a aqueous solution), such that a redox reaction occurs leading to one metal with the more negative electrode potential (the anode) becoming oxidized, while the other less negative potential (the cathode) is reduced.
In order for galvanic corrosion to occur, three elements are required.
i. Two metals with different corrosion potentials (anode and cathode)
ii. Direct metal-to-metal electrical contact
iii. A conductive electrolyte solution (e.g. water) must connect the two metals on a regular basis.
For example oxidation (corrosion) of aluminium wires when in contact with copper wire under wet conditions.
2. The most likely electrolyte will be rainwater containing dissoved solutes (if the panel is in an exposed part of the house) or damp/moist air.
3. From the table, the most likely screw will be chromium-plated steel screws or stainless steel (made of iron and nickel) screws or galvanized steel (zinc-plated) screws.
All these possible screw components have a more negative electrode potential than copper. Thus they will serve as the anode in a galvanic oxidation with copper.
