Answer:
n = 2 to n = 9
Explanation:
Atoms absorb energy when they move from a lower to a higher energy level. The magnitude of energy absorption depends on the difference in energy between the initial and final orbitals.
Hence; ∆E= Ef - Ei
Where;
Ef= energy of the final orbital
Ei= energy of the initial orbital
Considering the energy difference between n=9 and n=2, the highest amount of energy is absorbed during this transition.
Give one example of how studying chemistry could be
useful in everyday life
Answer:
Chemistry is used almost everywhere you go. from the car you use to get to work (gasoline burning) to the nuclear reactors that power many homes ( uranium becoming unstable to product electricity.
how potassium iodide aids the titration of the cyclohexane layer.
Answer:
to avoid iodine vapor from escaping.
Explanation:
This question is all about an experimental work on the determination of the distribution of iodine between waters and cyclohexane. To understand this question one has to understand the topic "Equilibrium" very well.
One important thing that must be noted in this question is for us to remember that water and cyclohexane are two immiscible liquids. So, when Iodine is added to the two solvents, the iodine dissolves in both water and cyclohexane to certain rate ands then to an equilibrium which is;
Kd = I₂[Cyclohexane]/ I₂[water]. ----------------------------------------[**].
There is a release of I⁻¹ From the added potassium iodide which helps in making sure that the iodine vapor does not escape. Thus, forming a tri-iodide ion.
In terms of atomic structure, explain why the first ionization energy K is less than that of Ca ?
Look at this picture and please help
Answer : The kinetic energy will be 24 J.
Explanation : Given,
Mass of marble = 3 kg
Velocity of a marble = 4 m/s
Formula used to calculate the kinetic energy is:
[tex]K.E=\frac{mv^2}{2}[/tex]
where,
K.E = kinetic energy
m = mass
v = velocity
Now putting all the given values in this formula, we get:
[tex]K.E=\frac{3kg\times (4m/s)^2}{2}[/tex]
[tex]K.E=24kg.m^2/s^2=24J[/tex] [tex](1J=1kg.m^2/s^2)[/tex]
Therefore, the kinetic energy will be 24 J.
Iron(III) oxide gets mixed with elemental carbon and heated to make elemental iron and carbon dioxide.
a) If they want to convert 1.00kg of iron (III) oxide to elemental iron, how much carbon needs to be added to the mix?
b) That 1.00kg of iron (III) oxide, with an excess of carbon, produces how much elemental iron.
Answer:
Explanation:
Iron(III) oxide gets mixed with elemental carbon and heated to make elemental iron and carbon dioxide.
2Fe₂O₃ + 3C = 4 Fe + 3 CO₂
2 x 160 3 x 12 4 x 56
320 gram of iron ( iii ) oxide requires 36 g of carbon for reduction
1 kg of iron will require 36 / 320 g of carbon
carbon required = 36 / 320 g
= .1125 g
= .113 g rounding off to 3 significant fig .
b )
320 gram of iron ( iii ) oxide produces 224 g of iron after reduction
1 g of iron will produce 224 / 320 g of iron
iron produced = 224 / 320 g
= 0.700 g .
Which of the following reactions is NOT a redox reaction? Question 25 options: SO3(g) + H2O(l) H2SO4(aq) Al(s) + 3Ag+(aq) Al3+(aq) + 3Ag(s) Ba(s) + Cl2(g) BaCl2(s) H2(g) + O2(g) H2O(g) Al(s) + Fe2O3(s) Fe(s) + Al2O3(s)
Answer:
SO3(g) + H2O(l) ------> H2SO4(aq)
Explanation:
'Redox' is a term used to describe reduction and oxidation since the both are complementary processes, one can not occur without the other.
A redox reaction is one in which there is a change in the oxidation number of the reactants from left to right of the reaction equation.
If we looks at the reaction;
SO3(g) + H2O(l) ------> H2SO4(aq)
There was no change in the oxidation numbers of species from left to right of the reaction equation. For instance, the oxidation state of sulphur is +6 on both sides of the reaction equation hence it is not a redox reaction.
Write the empirical formula of at least four binary ionic compounds that could be formed from the following ions:
Ca^2+, Cr^4+, Cl^-, S^2-
Answer:
[tex]$ CaCl_2$[/tex], CaS, [tex]$ Cr Cl_4$[/tex], [tex]$ CrS_2$[/tex]
Explanation:
The reaction can be done by adding the cations and the anions.
The binary compounds are always formed by the two different elements.
When one calcium ion, [tex]$ Ca ^{2+} $[/tex] combines with the two calcium ions, [tex]$ Cl^-$[/tex], they formed a binary compound of [tex]$ CaCl_2$[/tex].
When one [tex]$ Ca ^{2+} $[/tex] combines with one [tex]$S^{2-}$[/tex] ion, they formed CaS binary compound.
When one chromium ion [tex]$ Cr^{4+}$[/tex] combines with four ions of chlorine, [tex]$ Cl ^- $[/tex], the compound formed is [tex]$ Cr Cl_4$[/tex].
When 1 ion of [tex]$ Cr^{4+}$[/tex] combines with 2 ions of sulphur, [tex]$S^2$[/tex], the binary compound formed is [tex]$ CrS_2$[/tex].
Science always begins with what?
Step 7- Communicate. Present/share your results. Replicate.
Step 1- Question.
Step 2-Research.
Step 3-Hypothesis.
Step 4-Experiment.
Step 5-Observations.
Step 6-Results/Conclusion.
A stack of ten 3.5 in diskettes is 34 mm high. How many diskettes does it take to make a stack 100 yards high?
Answer:
3.5 divided by 34 then divide again 100
Explanation:
math
What color would the cyanidin indicator turn in an acidic solution?
Answer:
It would change to a strong Red color
Explanation:
Cyanidin indicators turn strong red in acidic solutions and blue or green in a basic environment
i need to know the measurements of this to the appropriate amount of significant figures
Answer:
[See Below]
Explanation:
140 ml.
bronze is a mixture of copper and tin. Would all bronze have the same melting point? Explain.
Answer:
its also a mixture of gold.
Explanation:
Which of the following statements is true concerning the reaction given below?2H2S(g) + O2(g) → 2S(s) + 2H2O(g)a. The reaction is second-order in H2S(g) and first-order in O2(g).b. The reaction is first-order in H2S(g) and second-order in O2(g).c. The rate law is Rate = k[H2S]2[O2].d. The rate law is Rate = k[H2S][O2].e. The rate law may be determined only by experiment.
Answer:
The rate law may be determined only by experiment.
Explanation:
For a reaction, A + B ---> C, the rate law can only be determined from experimental data. Chemists determine the rate of reaction by carefully observing the changes in the concentration of species as the reaction progresses.
Hence, the rate law is not determined by inspection of the chemical reaction equation, it must be obtained from the experimental data, hence the answer given.
suggest what the effect of using growth hormone on meat cattle might be
Answer:
Natural BGH and rBGH both increase the level of another hormone called insulin-like growth factor (IGF-1) in the cow.
Beef cattle are often given steroids to increase and speed growth. Common steroids include:
Natural steroids like estradiol, testosterone, and progesterone Man-made steroids from compoundsMajor groups such as FDA and Food and Agricultural Organization state track level of hormones in food. They state that the levels of hormones in food are safe to eat. Not everyone agrees.
Explanation:
Hormones are present in all animal products. Some are natural, others may be added through supplements. Hormones and steroids are given to livestock. It can increase the number of dairy products and beef.
FDA establishes the acceptable safe limits for hormones in meat. A safe level for human consumption is a level of drug in the meat that would be expected to have no harmful effect in humans based on extensive scientific study and review.
C-12 has 6 protons.
How many neutrons does C-13 have?
A. 6
B. 7
C. 13
D. 19
Answer:
B-7
Explanation:
13-6=7
Assume a healthy hearts beats exactly 70 times per minute. If individual lives to age 85 years, estimate the number of heartbeats in their lifespan using scientific notation and the correct number of sig figs.
Given :
Number of heart beat in 1 minute , n = 70 .
The individual lives for 85 years .
To Find :
The number of heartbeats in their lifespan .
Solution :
Now , number of minutes in one hour is 60 .
One day contains 24 hours .
Therefore , minutes in one whole day :
[tex]24\times 60 = 1440\ sec[/tex]
Now , 1 year contains 365 days .
( Note : We are not considering any leap years )
Minutes in one year are :
[tex]365\times 1440=525600=5.25\times 10^5\ sec[/tex]
So ,total minutes in 85 years is :
[tex]=5.25\times 10^5\times 85\\\\=4.46\times 10^7\ sec[/tex]
Hence , this is the required solution .
Which solvent caused the ink from the dots to move the most? Question 4 options: A) vegetable oil B) water C) alcohol D) half water, half alcohol
Answer:
half water, half alcohol
Explanation:
Some inks are water soluble while some are alcohol soluble. Inks that do not dissolve in water usually dissolve in alcohol.
If inks are to be separated by chromatography, we have to make the mobile phase a mixture of alcohol and water in order for the dots to move the most.
Answer:
alcohol
Explanation:
which of the following structures can differentiate plant and animal cells
Explanation:
plant cells are rigid in shape
animal cells are flexible in shape
animal cell are flexible because of their movement around
plant cells are rigid cause they stay without walking around
the quantity of 3.00 cm ^ 3 is the same _ mL
Answer:
3 mL
Explanation:
1 cubic centimeter (cm³) is equal to 1 milliliter (mL).
We want to find out how many milliliters 3 cm³ is equal to.
Since 1 cm³ is equal to 1 mL, 3 cm³ is equal to 3 mL.
The quantity of 3.00 cm³ is the same as 3 milliliters (mL).
Answer:
27 or [tex]3.00^{3}[/tex] (they're the same)
Explanation:
Write 3.00^3 out: [tex]3.00^{3}[/tex] [tex]3.00^{3}[/tex] = 3.00 × 3.00 × 3.00 = 27Convert 27 cm to mL: 27 × 1 = 27Therefore, 27 cm is the same as 27 mL.
what are the molecular formula of 20 elements
Explanation:
Hydrogen (H)
Helium (He)
Lithium (Li)
Beryllium (Be)
Boron (B)
Carbon (C)
Nitrogen (N)
Oxygen (O)
Fluorine (F)
Neon (Ne)
Sodium (Na)
Magnesium (Mg)
Aluminum (Al)
Silicon (Si)
Phosphorus (P)
Sulfur (S)
Chlorine (Cl)
Argon (Ar)
Potassium (K)
Calcium (Ca)
Hope this is correct and helpful
HAVE A GOOD DAY!
(5.391 ´ 10-7) + (2.5531 ´ 10-6) =
Answer:
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6}) = 3.0922 * 10^{-6}[/tex]
Explanation:
Given
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6})[/tex]
Required
Solve
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6})[/tex]
Remove the brackets
[tex]5.391 * 10^{-7} + 2.5531 * 10^{-6}[/tex]
Express [tex]10^{-7}[/tex] as [tex]10^{-1-6}[/tex]
[tex]5.391 * 10^{-1-6} + 2.5531 * 10^{-6}[/tex]
Apply law of indices
[tex]5.391 * 10^{-1} * 10^{-6} + 2.5531 * 10^{-6}[/tex]
[tex]0.5391 * 10^{-6} + 2.5531 * 10^{-6}[/tex]
Factorize:
[tex](0.5391 + 2.5531)10^{-6}[/tex]
[tex](3.0922)10^{-6}[/tex]
Remove bracket
[tex]3.0922 * 10^{-6}[/tex]
Hence:
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6}) = 3.0922 * 10^{-6}[/tex]
Calculate the density of a rock if it has a mass of 498g and a volume of 11.9 mL.
Answer:
Density = 41.8 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]From the question
mass = 498 g
volume = 11.9 mL
Substitute the values into the above formula and solve for the Density
That's
[tex]Density = \frac{498}{11.9} \\ = 41.8487[/tex]We have the final answer as
Density = 41.8 g/mLHope this helps you
I need help rearranging the following formulas to solve for the requested variable please
Answer :
Part (e): [tex]C_2=\frac{C_1\times P_2}{P_1}[/tex]
Part (f): [tex]P_2=\frac{C_2\times P_1}{C_1}[/tex]
Part (g): [tex]\text{Volume}=\frac{\text{Mass}}{\text{Density}}[/tex]
Explanation :
Part (e):
The given expression is:
[tex]\frac{C_1}{P_1}=\frac{C_2}{P_2}[/tex]
Now rearranging the the terms, we get:
[tex]C_2=\frac{C_1\times P_2}{P_1}[/tex]
Part (f):
The given expression is:
[tex]\frac{C_1}{P_1}=\frac{C_2}{P_2}[/tex]
Now rearranging the the terms, we get:
[tex]P_2=\frac{C_2\times P_1}{C_1}[/tex]
Part (g):
The given expression is:
[tex]\text{Density}=\frac{\text{Mass}}{\text{Volume}}[/tex]
Now rearranging the the terms, we get:
[tex]\text{Volume}=\frac{\text{Mass}}{\text{Density}}[/tex]
how do you make it so that 43200 ml have only 3 significant figures? I will give brainiest pls help
Answer:
3 sig figs
Explanation:
one of the rules for sig figs is a when a whole number has zeros if they are sandwiched between whole number for ex. 34007 they would all be sig figs. hope this helps!
btw all the zeros behind the decimal are significant for ex. 0.4800
Answer:
you could make it 43.2 x 10^2
Explanation:
Explain why NaBH4 is less reactive than LiAlH4 (Hint: write the structure of each ion, (BH4) - and (AlH4) - , with their formal charges
Answer:
See explanation
Explanation:
The ability of a hydride to act as a reducing agent depends on the electro negativity of the central atom in the complex hydride anion.
If we compare the electronegativities of Boron and Aluminum, Boron is more electronegative than aluminum. The more electronegative the central atom is, the lesser the electron density on the hydride and the lesser its ability to act as a reducing agent.
For the reason stated above, LiAlH4, having aluminium of low electro negativity as its central atom is a better reducing agent than NaBH4.
Rank the following compounds in order of reactivity toward nitration with HNO3:_______. thiophene, benzene, 3-methylthiophene, and 2-methylfuran.
Answer:
3-methylthiophene > thiophene > benzene > 2-methylfuran
Explanation:
Primarily, five membered heterocyclic aromatic rings undergo nitration at carbon-2. This is because, nitration at carbon-2 leads to the formation of three resonance structures while attack at carbon-3 yields only two resonance structures, hence it is less stabilized.
The presence of a methyl group which donates electrons promotes the stabilization of the cation formed in the nitration of 3-methylthiophene.
2-methylfuran is the least reactive towards nitration because the 2-position has been blocked by a methyl group.
Suggest what the effect of using growth hormone on meat cattle might be
It might affect the health of consumer of that meat. Hope it helps
If object A and object B have the same density, but object A has greater mass, then object A must have:
object A has a larger volume than object B
density is a ___ that ____ the ____ of an object to its ______
Answer:
density is a PROPERTY that DESCRIBES the MASS of an object to its VOLUME.
Explanation:
An eccentric chemistry professor (not mentioning any names) stops in every day and orders 200ml of Sumatran coffee at precisely 65.0°C. You then need to add enough milk at 7.00°C to drop the temperature of the coffee, initially at 85.0°C, to the ordered temperature. Calculate the amount of milk (in ml) you must add to reach this temperature. In order to simplify the calculations, you will start by assuming that milk and coffee have the specific heat and density as if water. In the following parts, you will remove these simplifications. Solve now this problem assuming the density is 1.000 g/ml for milk and coffee and their specific heat capacity is 4.184 J/(g ºC). How much milk will you add?
Answer:
68.97g of milk must be added
Explanation:
To solve this problem we need to use the equation:
Q = C*m*ΔT -Coffee cup calorimeter equation-
This equation relates mass and change in temperature with heat of solution, Q.
The energy that decreases in the milk is the same that increases in the milk. That is:
Q(milk) = Q(tea)
Using the equation:
4.184J/molK* Mass milk * (65.0°C - 7.00°C) = 4.184J /molK * 200g (Tea) * (85.0°C - 65.0°C)
Mass milk * 58.0°C = 200g * 20.0°C
Mass milk = 4000g°C / 58.0°C
Mass milk =
68.97g of milk must be added