Answer:
E = 5×10⁻¹⁹ J
Explanation:
Given data:
Wavelength = 400 nm (400×10⁻⁹ m)
Energy of wave = ?
Solution:
Formula:
E = h c/λ
c = 3×10⁸ m/s
h = 6.63×10⁻³⁴ Js
Now we will put the values in formula.
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s /400×10⁻⁹ m
E = 19.89×10⁻²⁶ J.m / 400×10⁻⁹ m
E = 0.05×10⁻¹⁷ J
E = 5×10⁻¹⁹ J
How would one use a Grignard-based synthesis to accomplish the following transformation? benzyl bromide (PhCH2Br) to 3-phenyl-1-propanol 1. Mg, Et20 2. ethylene oxide3. H3O+ 1. Mg, Et2O 2. Ethanol3. H3O+ 1. Mg, Et202. Ethylene 3. H3O+ None of the above.
Answer: ghfbg
Explanation: fgfghfg
An example of a suspension is a ____
A)chemical b)heterogenous
c)homogenous d)salad
Answer:
b
Explanation:
suspension is the heterogenos solution
what is the mass of silver that has a volume of 238mL? the density of silver is 10.5 g/cm^2
Explanation:
What volume of silver metal will weigh exactly 2500.0 g. The density of silver is 10.5 g/cm3. cm3 = 2500.0 g / 10.5 g/cm3 = 238 cm3
What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3? d = .85 g/cm3
I have 2 samples of solid chalk (aka calcium carbonate). Sample A has a total mass of 4.12 g and Sample B has a total mass of 19.37 g. What is the difference between the samples?
A) Sample B has more calcium carbonate molecules
B) Sample B has a larger ratio of carbon, oxygen, and calcium atoms
C) Sample B has more calcium ion than carbonate ions
D) Sample B must have some impurity
Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}\ \text{mol}^{-1}[/tex]
For the 4.12 g sample
Moles of a substance is given by
[tex]n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}[/tex]
Number of molecules is given by
[tex]nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}[/tex]
For the 19.37 g sample
[tex]n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}[/tex]
Number of molecules is given by
[tex]nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}[/tex]
[tex]1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}[/tex]
So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
2. Which of the following would produce a precipitate when mixed water (H20)?
A) HNO3
B) Br2
C) BaS
D) PbBr2
3.Given that the reaction below is a precipitation reaction, what is the missing symbol?
Li2CO3 (aq) + BaS (aq) - > LiOH (aq) + BaCo3 (?)
Answer: #2 : s, solid & #3 : PbBr2
Explanation:
In the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.
What is chemical reaction?Chemical reaction is defined as a procedure that involves changing a substance's molecular or ionic structure, as opposed to changing its physical shape or undergoing a nuclear reaction. When atoms establish or break chemical bonds, chemical reaction take place. Reactants are the substances that begin a chemical reaction, while products are the compounds that are created as a result of the reaction.
Precipitation is defined as the mechanism by which water vapor in the atmosphere condenses and descends to the ground under the pull of gravity. Water vapor in the clouds condenses into increasing-sized droplets of water, forming precipitation. To replenish the water on the earth, precipitation is required. This world would be a vast desert if it didn't rain. Within an estuary, water level and water quality are impacted by the frequency and length of precipitation events.
Thus, in the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.
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On a statistical basis,smoking a single cigarrette lowers your life expectancy by 642,000--------------------------.Pls answer this question
Thank you, also what are the options then I can help!
Given the reaction _K(s) +_ Cl2(g) → _KCl(s) what is the amount of K, in grams, needed to completely react with 2 moles of Cl2(g)?
Answer:
156.4g K
Explanation:
I'm not sure if it is correct but I think it should be this
What do we know so far?: 2K + 1Cl2 -> 2KCl, 2 mol of Cl2
What are we looking for?: #g of K
What is the ratio of K to Cl2?: 2:1
Set up equation: 2molCl2 x [tex]\frac{2mol K}{1 mol Cl2}[/tex]
Cancel unwanted units: 2 x [tex]\frac{2mol K}{1}[/tex]
Answer we got: 2 x 2mol K = 4mol K
Converting moles to grams: 4 x 39.1 (molar mass of K) = 156.4g K
Draw conclusion: The density of water is 1.0 g/mL, or 1.0 g/cm². Look at the data in your table. How can you use the density of an object to predict whether it will sink or float?
(Data is above)
PLEASE HELP
Answer:
work out if it's either going to sink or float
Explanation:
this can be carried out by calculating the numbers
Solution A is 100 times as acidic as solution B. What is the difference in pH values of solution A and solution B
Answer:
The difference is 2 pH units.
Explanation:
Let's give an arbitrary value to the H⁺ concentration of solution A, [H⁺]ₐ:
[H⁺]ₐ = 0.001 MIf that's the case then the pH of solution A would be:
pHₐ = -log(0.001) = 3----
The H⁺ concentration of solution B ( [H⁺]ₓ ) is 100 higher than that, so:
[H⁺]ₓ = 0.001 * 100 = 0.1 MAnd its pH:
pHₓ = -log(0.1) = 1So the difference in pH values is:
pHₐ - pHₓ = 3 - 1 = 2Which statement best describes heating by conduction?
1. Sunlight travels through space without the aid of fluids or solids.
2. Air at the equator rises and sinks at the poles.
3. Air molecules touch the warm ground, heating them up.
4. Warm air rises and takes heat with it; eventually it cools and sinks.
(If you want brainliest please explain why the answer is that answer)
Answer:
It would be A. Air molecules touch the warm ground, Heating them up because conduction is when a source of energy touches something directly.
Answer:
3. Air molecules touch the warm ground, heating them up.
Explanation:
Plate Tectonics Lab Report
Instructions: In the Plate Tectonic lab you will investigate the interactions between continental and oceanic plates at convergent, divergent, and transform boundaries around the globe. Record your observations in the lab report below. You will submit your completed report.
Name and Title:
Include your name, instructor's name, date, and name of lab.
Kaleb, Ms. Young, 11/25/2020, Plate Tectonics Lab Report
Objective(s):
In your own words, what was the purpose of this lab?
To look at interactions between continental and oceanic plates.
Hypothesis:
In this section, please include the if/then statements you developed during your lab activity for each location on the map. These statements reflect your predicted outcomes for the experiment.
Location One: Select three events that you predict will be observed. If I explore two continental plates at a convergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Two: Select three events that you predict will be observed. If I explore two continental plates at a divergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Three: Select three events that you predict will be observed. If I explore two continental plates at a transform boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Four: Select two events that you predict will be observed. If I explore two oceanic plates at a convergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Five: Select three events that you predict will be observed. If I explore two oceanic plates at a divergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Six: Select two events that you predict will be observed. If I explore two oceanic plates at a transform boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Procedure:
The procedures are listed in your virtual lab. You do not need to repeat them here. Please be sure to identify the test variable (independent variable), outcome variable (dependent variable).
Reminder: Test variable = the item you are changing or manipulating; Outcome variable = the item you are measuring
Test variable (independent variable):
Outcome variable (dependent variable):
Data:
Record the data from each location below.
Location Name
Boundary Type
(C=Convergent, D=Divergent, or T=Transform)
Year Observed
(5, 10, or 20 million years)
Geologic Events Observed
(earthquakes, faults, ocean formation, mountains, volcanoes, island chains, seafloor spreading)
Location One
Himalayas
5
Event 1-
20
Event 2-
Location Two
East Africa
5
Event 1-
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Five: Select three events that you predict will be observed. If I explore two oceanic plates at a divergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Six: Select two events that you predict will be observed. If I explore two oceanic plates at a transform boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Procedure:
The procedures are listed in your virtual lab. You do not need to repeat them here. Please be sure to identify the test variable (independent variable), outcome variable (dependent variable).
Reminder: Test variable = the item you are changing or manipulating; Outcome variable = the item you are measuring
Test variable (independent variable):
Outcome variable (dependent variable):
Data:
Record the data from each location below.
Location Name
Boundary Type
(C=Convergent, D=Divergent, or T=Transform)
Year Observed
(5, 10, or 20 million years)
Geologic Events Observed
(earthquakes, faults, ocean formation, mountains, volcanoes, island chains, seafloor spreading)
Location One
Himalayas
5
Event 1-
20
Event 2-
Location Two
East Africa
5
Event 1-
Please answer quickly!!!
I will award 50 points!
Answer:
In this section, please include the if/then statements you developed during your lab activity for each location on the map. These statements reflect your predicted outcomes for the experiment.
Location One: Select two events that you predict will be observed. If I explore two continental plates at a convergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Two: Select three events that you predict will be observed. If I explore two continental plates at a divergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Three: Select three events that you predict will be observed. If I explore two continental plates at a transform boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
This is all I have for now! Hope this can help! :)
It is possible for gases in the atmosphere to change the behavior of energy on earth. Agree or disagree
Answer:
I agree
Explanation:
because the sunlight passes through the atmosphere and is absorbed by earth's surface.
The green house gases in the atmosphere can change the behavior of energy on earth. Thus i agree with this statement.
What is green house effect?The green house effect is defined as a process by which the radiations from the sun are absorbed by the green house gases like methane, Chloro fluoro carbons and not reflected back into the space. This makes the surface as insulator and prevents it from freezing.
Due to the increased level of green house gases, the temperature of the earth increases considerably and thereby causes global warming, depletion of ozone layer, smog and air pollution, etc.
It is the natural green house effect which affect the behaviour of heat energy radiated by the sun. The green house gases never let the radiations escape from the earth and increase the surface temperature of earth. This leads to global warming.
Thus green house gases affects the solar energy.
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Which sentence is punctuated correctly? A. I bought all the ingredients for dinner, eggs, tomatoes, macaroni, and cheese and told Molly to preheat the oven. B. I bought all the ingredients for dinner: eggs, tomatoes, macaroni, and cheese—and told Molly to preheat the oven. C. I bought all the ingredients for dinner eggs, tomatoes—macaroni, and cheese and told Molly to preheat the oven. D. I bought all the ingredients for dinner (eggs, tomatoes), macaroni, and cheese and told Molly to preheat the oven.
The sentence that has an accurate punctuation is found in (Option B).
What are punctuation marks?The punctuation marks are those marks that are use to make a piece of writing to have a complete meaning. A piece of writing will be meaningless if there are no attached punctuation marks.
The sentence that is correctly punctuated is; "I bought all the ingredients for dinner: eggs, tomatoes, macaroni, and cheese—and told Molly to preheat the oven."(Option B)
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PLZ HELP ASAP
Which would increase the reaction rate?
Check all that apply.
A. Stirring the reaction
B. Raising the activation energy
O C. Adding a catalyst
D. Raising the temperature
Answer:
adding a catalyst will increase the reaction rate.
Explanation:
im like 95% sure thats right.
Answer:
A. C. D
Explanation:
ap ex
Suppose the Cu ions are produced by the reaction of 0.94 g of copper turnings with excess nitric acid. How many moles of Cu are produced?
Answer:
0.0148 moles
Explanation:
Solid copper is oxidized with HNO₃:
Cu + 4HNO₃ → Cu²⁺ + 2 NO₃⁻ + 2H₂O + 2NO₂
Where 1 mole of Cu produce 1 mole of Cu²⁺ when nitric acid is in excess.
Moles of Cu that react (Molar mass Cu = 63.546g/mol):
0.94g * (1mol / 63.546g) = 0.0148 moles of Cu
And moles of Cu²⁺ produced are also:
0.0148 molesArrange in order of decreasing atomic radii: Kr, K, Ge, Ca
Answer:
K > Ca > Ge > Kr
Explanation:
The elements given are all in the 4th period on the periodic table.
Kr, k, Ge, Ca;
Arranging their order from left to right;
K, Ca, Ge, Kr
Atomic radius is taken as half the of the inter-nuclear distance (d) between two covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.
Across the periodic table atomic radii decreases progressively from left to right. This is due to progressive increase in the nuclear charge (number of protons in the nucleus) without an attendant increase in the number of electronic shells.
From the left to right; decreasing radii;
K > Ca > Ge > Kr
Balance the reaction:
Ag + H2S + O2 > Ag2S + H2O
Answer:
the given reaction after balancing is:
4Ag + 2H2S +O2 > 2AG2S +2H2O
Explanation:
4Ag=Ag
2H2=2H2
O2=20
2S=2S
I hope that you will understand that.
Which units can be used to describe the thermal
energy within a substance?
Answer: Btu, British Thermal Unit is used to express thermal energy when working in pounds and degrees Farenheit.
Calories are used when working in grams and degrees Centigrade or Kelvin (SI units)
A Joule is the British system unit used to measure heat transfer.
Explanation:
What is the mass of florine
Answer:
18.998403
is the mass
The ingredients of a soup include
1,500 grams of water, 350 grams of vegetables, and 210 grams of meat. What is the total mass of the soup?
Answer:
sopas
Explanation:
lagyan mo ng condense
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the total mass of the soup is 2,060gram.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.
mass of soup= mass of water+ mass of vegetables + mass of meat
mass of water=1,500 grams
mass of vegetables= 350 grams
mass of meat=210 grams
substituting all the values in the above equation, we get
mass of soup= 1,500 grams+ 350 grams + 210 grams
= 2,060gram
Therefore, the total mass of the soup is 2,060gram.
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Balance chemical equation hbr(aq)+o2(g) h20(l)+br2(l)
An atom of an element contains 20 protons, 20 neutrons, and 20 electrons. This element is in Group *
Answer:
it is calcium. it is in group(llA).
Answer:
calcium it lies in group(IIA)hope it is helpful to you
in the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely
Answer:
When there is no spark from the reaction
Explanation:
The reaction between the acid and the magnesium metal goes into completion when there is no more spark from the magnesium. Also, the magnesium would have totally disappeared into solution.
These physical observation marks the end of the reaction.
When Mg reacts with HCl hydrogen bubbles are released. The completion of the given reaction can be determined by the presence of bubbles above the HCl.
The reaction between HCl and Mg:[tex]\bold {Mg+ 2HCl\rightarrow MgCl_2 + H_2}[/tex]
In this reaction, Mg reacts with 2 moles of HCl to form 1 mole of Magnesium chloride and release hydrogen gas.
During reaction,
Magnesium slowly disappears as it reacts with HCl.The hydrogen gas is released during the reaction, bubbles can be observed.Therefore, the completion of the given reaction can be determined by the presence of bubbles above the HCl.
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Which of the following is the best definition of a chemical change?
A. A change in a substance where no new substance forms
B. A change in a substance where energy is conserved
C. A change in a substance where a phase change occurs
D. A change in a substance where one or more new substances form
Answer:it's D
Explanation:
A chemical change, unlike a physical change, is the formation of new products or one or more new substances formed from the reactants. Thus, option D is correct.
What is a chemical change?A chemical change is a type of change where the reactants break or combine to form a new product that is different from the reactants. Unlike physical change, they are not reversible and can be seen in combustion, neutralization, decomposition, redox reactions, etc.
It is a change in a matter where the reactant undergoes breaking or forming of the bonds to yield a new product. It is accompanied by changes in temperature, color, precipitation, and odor.
Therefore, a chemical change results in the formation of a new substance.
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liquid to gas require heat?
Answer:
yes
Explanation:
Answer:
yes
Explanation:
let's say you have ice, you put it on a pan then it heats up you get a liquid after a while it turns into a gas
Choose ALL the answers that apply.
Sound _____.
travels in transverse waves
requires a medium to travel through
travels most slowly through solids
speeds up when temperature is increased
is changed into electrical impulses by the cochlea
Answer:
Speeds up when temperature is increased and can travel through a solid
Explanation:
How many different principal quantum numbers can be found in the ground-state electron configuration of nickel?A) 2.B) 3.C) 4.D) 5.E) 6.
Answer:
C) 4.
Explanation:
Hello!
In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:
[tex]Ni^{28}:1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^8[/tex]
We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.
Therefore, nickel has C) 4 different principal quantum numbers.
Best regards!
Sulfite is similar to hydroxide in its behavior as a ligand: most sulfites are insoluble in water, but excess sulfite can result in the formation of a complex ion. Write the two equilibrium reactions of sulfite with the copper(II) ion that show this behavior.
Answer:
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
Explanation:
A ligand may be defined as a molecule or an ion or that binds to the central metal atom in order to form a more coordination complex. Sulfite is one such ligand and it behaves similarly as hydroxide as a ligand.
Now, according to the question, when we react copper with sulfite ion, it forms copper sulfite. The equation is
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
Now when excess of the sulfite ion is used in the reaction, we get a complex formation, which is shown by
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
The way the sulfite reacts is quite similar to hydroxide ion where they form a complex ion when hydroxide ion in excess is used in the reaction with metal cation.
Please help me on question #2 please please really need help due today at 9:00pm please
1Water molecules can be ligands especially when they are bonded to
..........
A. alkaline earth metals
B. alkali metals
C. transition metals
D. group VII elements
Answer:c
Explanation: