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kenny6666 [7]
4 years ago
5

PLEASE!!!!

Chemistry
2 answers:
Ede4ka [16]4 years ago
7 0
The answer the comes closest to being correct would be answer choice D. the problem with it though is that it does not have the correct amout of neurtrons. It is called rubidium 87 therefor there must be 50 neurtrons if there are 37 electrons and protons 87-37=50, 50+37=87.
kolbaska11 [484]4 years ago
3 0

it's d. taking the test and you have a typo. D should be 50 neutrons not 40

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In the flame test, barium ions produce a green flame whereas calcium ions produce a red flame. In your own words, explain these
deff fn [24]

Answer:

The Barium flame is green because it is a difficult flame to excite, therefore for it to trigger a flame it is necessary that it be too excited for it to occur.

The reddish color of calcium is due to its high volatility and it is sometimes very difficult to differentiate it from strontium.the compression of these elements is due to being able to make them work during combustion

Explanation:

The flame test is a widely used qualitative analysis method to identify the presence of a certain chemical element in a sample. To carry it out you must have a gas burner. Usually a Bunsen burner, since the temperature of the flame is high enough to carry out the experience (a wick burner with an alcohol tank is not useful). The flame temperature of the Bunsen burner must first be adjusted until it is no longer yellowish and has a bluish hue to the body of the flame and a colorless envelope. Then the tip of a clean platinum or nichrome rod (an alloy of nickel and chromium), or failing that of glass, is impregnated with a small amount of the substance to be analyzed and, subsequently, the rod is introduced into the flame, trying to locate the tip in the least colored part of the flame.

The electrons in these will jump to higher levels from the lower levels and immediately (the time that an electron can be in higher levels is of the order of nanoseconds), they will emit energy in all directions in the form of electromagnetic radiation (light) of frequencies characteristics. This is what is called an atomic emission spectrum.

At a macroscopic level, it is observed that the sample, when heated in the flame, will provide a characteristic color to it. For example, if the tip of a rod is impregnated with a drop of Ca2 + solution (the previous notation indicates that it is the calcium ion, that is, the calcium atom that has lost two electrons), the color observed is brick red .

3 0
3 years ago
Read 2 more answers
Convert 533 cm/s to units of meters per minute. Show the unit analysis by dragging the conversion factors into the unit‑factor s
lukranit [14]

Answer:

319.8 m/min

Explanation:

533 cm/s

We can convert 533 cm/s to m/min by doing the following:

First, we shall convert 533 cm/s to m/s. This can be obtained as illustrated below:

Recall:

100 cm/s = 1 m/s

Therefore,

533 cm/s = 533 cm/s /100 cm/s × 1 m/s

533 cm/s = 5.33 m/s

Finally, we shall convert 5.33 m/s to m/min. This can be obtained as follow:

1 m/s = 60 m/min

Therefore,

5.33 m/s = 5.33 m/s / 1 m/s × 60 m/min

5.33 m/s = 319.8 m/min

Therefore, 533 cm/s is equivalent to 319.8 m/min

8 0
3 years ago
Comment Both propane and benzene are hydrocarbons. As a rule,
kozerog [31]

The enthalpy change : -196.2 kJ/mol

<h3>Further explanation  </h3>

The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation  

The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)  

(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)  

The value of ° H ° can be calculated from the change in enthalpy of standard formation:  

∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)  

Reaction

2 H₂O₂(l)-→ 2 H₂O(l) + O₂(g)

∆H ° rxn = 2. ∆Hf ° H₂O - 2. ∆Hf °H₂O₂

\tt \Delta H_{rxn}=2.(-285.8)-2.(-187.8)\\\\\Delta H_{rxn}=-571.6+375.4=-196.2~kJ/mol\rightarrow \Delta Hf~O_2=0

5 0
3 years ago
What is gold atomic number
Korolek [52]

Answer:

79

Explanation:

6 0
3 years ago
Which sub-layer thins out into space, where there is no air
KengaRu [80]
<span>The "exosphere" is the most distant and tenuous "layer" of our atmosphere.</span>
3 0
3 years ago
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