Answer:
1.reaction with energy 2. one substance breaks down 3. reaction to acid and base
Answer:
Noble gas, any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og). The noble gases are colourless, odourless, tasteless, nonflammable gases. They traditionally have been labeled Group 0 in the periodic table because for decades after their discovery it was believed that they could not bond to other atoms; that is, that their atoms could not combine with those of other elements to form chemical compounds. Their electronic structures and the finding that some of them do indeed form compounds has led to the more appropriate designation, Group 18.
interactive periodic table
Answer:
The hydrogen spectrum is an important piece of evidence to show the quantized electronic structure of an atom. ... It results in the emission of electromagnetic radiation initiated by the energetically excited hydrogen atoms. The hydrogen emission spectrum comprises radiation of discrete frequencies.
The spectrum starts with red light, with a wavelength of 700 nanometers (7,000 angstroms), at the top. ... It spans the range of visible light colours, including orange and yellow and green, and ends at the bottom with blue and violet colours with a wavelength of 400 nm (4,000 angstroms).
Explanation:
Hydrogen molecules are first broken up into hydrogen atoms (hence the atomic hydrogen emission spectrum) and electrons are then promoted into higher energy levels. Suppose a particular electron is excited into the third energy level. It would tend to lose energy again by falling back down to a lower level.
The spectrum of the Sun appears as a continuous spectrum and is frequently represented as shown below. This type of spectrum is called an emission spectrum because what you are seeing is the direct radiation emitted by the source.
Answer:
a. 1.728 moles.
b. 262.7g of Cr₂O₃ are required
Explanation:
Based on the reaction:
Cr₂O₃(s) + 3H₂S(g) → Cr₂S₃(s) + 3H₂O(l)
The important thing in the reaction is that 1 mole of Cr₂O₃ produce 1 mole of Cr₂S₃
a. To produce 346g of Cr₂S₃ we must know how many moles of Cr₂S₃ must be produced, and, as 1 mole of Cr₂O₃ produce 1 mole of Cr₂S₃ we can know moles of Cr₂O₃ that are required.
<em>Moles of 346g Cr₂S₃ (Molar mass: 200.19g/mol):</em>
346g Cr₂S₃ * (1mol / 200.19g) = 1.728 moles of Cr₂S₃
Based on the reaction, moles of Cr₂O₃ that are required are
<h3>
1.728 moles of Cr₂O₃</h3>
b. Again, to conver the 1.728 moles of Cr₂O₃ to grams we must use molar mass of Cr₂O₃ (151.99g/mol):
1.728 moles Cr₂O₃ * (151.99g / mol) =
<h3>262.7g of Cr₂O₃ are required</h3>