In the flame test, barium ions produce a green flame whereas calcium ions produce a red flame. In your own words, explain these observations in terms of the electron structure of these two ions. In other words explain how these different colors are produced and why using your understanding of atomic structure.
Answers
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 .
Answer:
The different colours produced come from the different wavelength of the spectrum of light as the excited electrons in the metals return to their original state on cooling down.
Explanation:
The flame test is an analytical procedure used to identify different metals by passing them through a flame.
The flame, which is a source of heat energy heats up the metals and excites their outermost electrons which transit to the next energy level. On cooling down, as the excited electrons return to their original state, they emit different colours corresponding to the spectrum of light. Electrons of larger atoms like Barium emit light of higher frequency and lower wavelength and hence exhibits colours closer to the ultraviolet part of the electromagnetic spectrum while smaller atoms like Calcium emit light of lower frequency and higher wavelength and emit light closer to the infrared part of the spectrum
Baruim (atomic number 56) and Calcium (atomic number 20) are both metals in group two of the periodic table.
They both have two electrons in their outermost shell and are represented by Ba²⁺ and Ca²⁺.
When both metals are passed to through the flame test, the two outermost electrons in both metals are excited.
However because the outermost electrons in Barium are farther to the nucleus than those in Calcium, it takes a lesser amount of heat energy to excite them than that of Calcium which is closer to the nucleus.
The spectrum of light which is usually represented by 'ROYGBIV' has the following colours : Red, Orange,Yellow, Green, Indigo and Violet with Red having their highest wavelength (or shortest frequency) and Violet the shortest wavelength (or highest frequency).
Barium's green colour is because it outermost electrons emit light in the range of the Green spectrum of light and calcium's red colour is because its outermost electrons emit light in the range of the Red spectrum of light
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Predict what kind of energy process happens when Lye, NaOH(s) is put in water and the water gets hot
b. using pure water
c. blowing on the hot water
d. putting the powder and hot water in a mixer
Answers
A , i think because pure water won't dissolve the powder fast.
b. It would have six electrons in the innermost shell.
c. It would have eight electrons in the outermost shell.
d. It would have eight electrons in the innermost shell.
Answers
oxygen atomic number is 8.
electron configuration of O is 2,6
therefore O has 6 valence electrons. valence electrons are electrons in the outermost shell that are involved in chemical bonds
atoms to become stable should fulfill the octet rule. This is where the outermost shell should have 8 electrons
so atoms with incompletely filled outer shells take part in chemical bonds to gain a complete octet and to become stable
So O too after forming a chemical bond would have 8 electrons in the outermost shell.
correct answer is
c. It would have eight electrons in the outermost shell.
Answer: I know I'm too late but for all you people that have an exam it is C.
Explanation:
The theoretical yield is calculated from the amount of the excess reactant present.
The theoretical yield is calculated from the amount of the limiting reactant present.
Answers
Answer: the fourth stament, The theoretical yield is calculated from the amount of the limiting reactant present.
Justification:
1) Limiting reactant is the one that is in less proportion than the theoretical mole ratio.
2) Excess reactant is the one that is in greater proportion than the theoretical ratio.
3) For example, if you have the equation A + 2B → C, means that 1 mol of A react with 2 moles of B to yield 1 mol of C.
As per that equation, the theoretical mole ratio is 1 mol of A : 2 moles of B : 1 moles of C.
If the actual amounts of A and B were 2 and 4, respectively, they were in the same ratio as the theoretical ratio, and all of the both reactants could react.
But if you had, for example, 2 moles of reactant A and 2 moles of reactant B, only one of the moles of A could react with the 2 moles of B, so B would be the limiting reactant: the whole 2 moles of B would react, while only 1 mole of A would reactant, and 1 mole of A would be left over (A is in excess).
Therefore, you cannot use the 2 moles of A to calculate the theoretical yield (since only 1 mole reacted), instead you must use the limiting reactant (B), which is the one that reacts completely.
earth?
A
It's oxygen
B
its hydrogen gas
C
It's carbon dioxide
D
It's water
Answers
Answer:
a
Explanation:
it's the most common thought of element when you need a compound from earth
B. atoms of an element can have different numbers of protons
C. atoms are divisible
D. all atoms of an element are not identical but they must all have the same mass
Answers
Answers
Neutron capture reactions.
Explanation
Isotopes of the same element have the same number of protons in each nucleus. However, their nucleus differ in the number of neutrons. Adding one or more neutrons to a nucleus will converts it to a different isotope of the same element.
Neutrons can be produced with a particle accelerator. The researcher might aim fast moving alpha particles from the accelerator at a beryllium Be target.
Doing so will convert beryllium-9 to carbon-12 and release one neutron.
The neutron produced in this process moves very fast ("fast neutrons"). It might knock protons or alpha particles off the target nucleus. This is undesirable since the nucleus will have a change in its proton number. It will end up belonging to a different element.
The researcher should reduce the speed of those neutrons. Passing neutrons through moderators greatly reduces their speed. Moderators are materials that are rich in light nuclei. They remove the energy of neutrons as the two collide. Examples of moderators are heavy water (D₂O) and graphite (carbon). Slow neutrons are easier to capture than fast-moving ones. Combining those slow-moving neutrons to the source isotope will likely produce a different isotope of the same element.
Reference
Vitz, Ed. et. al, "19.5: Neutron Bombardment", ChemPRIME (Moore et al.), Libretexts Chemistry, 2017
Answer:
D. BY ADDING OR REMOVING NEUTRONS.
Hope this helps!
Explanation: