Answer:
λ = 2.38 × 10^(-7) m
Explanation:
We are given the work function for palladium as 503.7 kJ/mol.
Now let's convert this to KJ/electron.
We know from avogadro's number that;
1 mole of electron = 6.022 × 10^(23) electrons
Thus,
503.7 kJ/mol = 503.7 × 1/(6.022 × 10^(23)) = 8.364 × 10^(-22) KJ/electron = 8.364 × 10^(-19) J/electron
Formula for energy of a photon is;
E = hv
Where;
h is Planck's constant = 6.626 × 10^(-34) J.s
v is velocity
Now, v = c/λ
Where;
c is speed of light = 3 × 10^(8) m/s
λ is wavelength of light.
Thus;
E = hc/λ
Making λ the subject, we have;
λ = hc/E
λ = (6.626 × 10^(-34) × 3 × 10^(8))/(8.364 × 10^(-19))
λ = 2.38 × 10^(-7) m
True or false The atomic number of an element is always more than the mass number of that element.
In an electrically neutral atom, the number of
protons equals the number of neutrons.
protons equals the number of electrons.
neutrons equals the number of electrons.
A. Protons equals the number of neutrons
B. Protons equal the number of electrons
C. Neutrons equals the number of electrons
Answer: B
Answer:
B
Explanation:
because protons have a +1 charge and electrons have a -1 charge, so if an atom is neutral it must have the same amount of protons and neutrons
Why does every chemical reaction require a certain amount of activation energy?
Explanation:
Activation energy is the minimum amount of energy required for a chemical reaction to take place.
When a chemical reaction occurs then bonds between the reactants break and bonds between the products are formed. This leads to the formation of an activated complex which is also known as transition state.
So, in order to form the activated complex a minimum amount of energy is necessary and this energy is known as activation energy.
If an atom has 32 protons in the nucleus, how many electrons will it have orbiting the nucleus
An atom is neutral as it has the same number of electrons that of protons. So, if an atom has 32 protons i.e. the atomic number of it is 32, then it will have 32 electrons revolving the nucleus.
What do we need in order to obtain energy?
Explanation:
hope it helps thanks ❤
brainliest please
Answer:
Explanation:
human obtains energy by eating food. as food is digested n broken down in our digestive system, energy is released to our body.
calculate the final pressure of a gas that is expanded from 725cm³ at 30C and 1.19 atm to 1.12cm³ at 43C
Answer:
Final pressure, P2 = 1088.89 atm
Explanation:
Given the following data;
Initial volume, V1 = 725 cm³Initial temperature, T1 = 30°CInitial pressure, P1 = 1.19 atmFinal volume, V2 = 1.12 cm³Final temperature, T2 = 43°CTo find the final pressure (P2), we would use the combined gas law.
Mathematically, the combined gas law is given by the formula;
[tex] \frac {PV}{T} = k [/tex]
[tex] \frac {P_{1}V_{1}}{T_{1}} = \frac {P_{2}V_{2}}{T_{2}} [/tex]
Substituting into the formula, we have;
[tex] \frac {1.19*715}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] \frac {850.85}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] 28.3617 = \frac {P_{2}*1.12}{43} [/tex]
Cross-multiplying, we have;
[tex] 28.3617 * 43 = 1.12P_{2} [/tex]
[tex] 1219.5531 = 1.12P_{2} [/tex]
[tex] P_{2} = \frac {1219.5531}{1.12} [/tex]
Final pressure, P2 = 1088.89 atm
Using the balanced equation below, how many grams of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride?
CSF + XeF6 → CsXeF7
Answer: A mass of 84.46 g of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride.
Explanation:
Given: Mass of cesium xenon heptafluoride = 73.1 g
The molar mass of cesium xenon heptafluoride is 131.3 g/mol. So, moles of [tex]CsXeF_{7}[/tex] is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{73.1 g}{131.3 g/mol}\\= 0.556 mol[/tex]
According to the given equation, 1 mole of CsF yields 1 mole of [tex]CsXeF_{7}[/tex].
Hence, moles of CsF reacting will also be equal to 0.556 mol. As molar mass of CsF is 151.9 g/mol so its mass is calculated as follows.
[tex]Moles = \frac{mass}{molarmass}\\0.556 mol = \frac{mass}{151.9 g/mol}\\mass = 84.46 g[/tex]
Thus, we can conclude that a mass of 84.46 g of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride.
HELP ASAP!! PLZ
What information is needed to determine a molecular formula?
A. The empirical formula and the molarity of the solution
B. The empirical formula and the empirical formula mass
C. The empirical formula and the percent composition
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D. The empirical formula and the molar mass
SUBMIT
D. The empirical formula and the molar mass
Boiling the solution causes the equilibrium in the following reaction to shift to the ________. HCO3- H3O --> H2CO3 H2O
Answer:
Right
Explanation:
The reaction of bicarbonate ion with acid is shown in the following equation;
HCO3- + H3O --> H2CO3 + H2O
This reaction is endothermic. This implies that energy must be absorbed from the surrounding as the reaction progresses.
Hence, when the solution is boiled, energy is supplied to the system in the form of heat and the forward reaction is favoured hence the equilibrium shifts to the right.
Which statement is the best description of a chemical bond
For a reaction, AH = 176 kJ/mol and A SO = 0.285 kJ/(K•mol). At what
temperatures is this reaction spontaneous?
A. At no temperature
B. T< 50 K
C. T> 617 K
D. T< 617K
The molar mass of oxygen(O) is 32g. What is the mass of 1.05*10^25 molecules of O²
Answer:
Hope that will help you
Explanation:
Text me for more answers
You react 25.0 grams of aluminum with iron (II) chloride. How many grams of iron will you
make? 2A1 + 3FeCl2 --> 2AlCl3 + 3Fe
(PLS HELP ASAP)
Explanation:
hope the picture above helps you to understand:)
7. Explain the difference between an ionic compound and a molecule, on an atomic
level (that is, describe what is happening with the atoms that makes these compounds
different)
Answer:
bakit Kay's lahat Ng module mahirap
How many of each kind of atom is in one molecule of water? 1 hydrogen atom and 2 oxygen atoms 1 hydrogen atom and 1 oxygen atom 2 hydrogen atoms and 1 oxygen atom 2 hydrogen atoms and 2 oxygen atoms
Answer:
What period is the atom in?
1.
What group is the atom in?
What is the name of this atom?
What other atom would have similar
properties to the atom?
Will this atom conduct electricity well
Explanation:
How many of each kind of atom is in one molecule of water? 1 hydrogen atom and 2 oxygen atoms 1 hydrogen atom and 1 oxygen atom 2 hydrogen atoms and 1 oxygen atom 2 hydrogen
and 2 oxygen atoms
ayuda, ayuda, ayuda urgente tengo 5 minutos necesito el nombre de lo que viene en las imágenes
Answer:huh
Explanation:
Determine the enthalpy for the reaction A+B --> C If we know the following:
A+E --> C+D; delta H = -200 kJ
D+B --> E; delta H = -100 kJ
Explanation:
here is the answer to the question
Glycerin, , is a nonvolatile liquid. What is the vapor pressure of a solution made by adding glycerin to at
Complete question is;
Glycerin, C3H8O3, is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 164 g glycerin to 338 mL H2O at 39.8°C?
The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.0992 g/cm³
Answer:
28 torr
Explanation:
Let's first find the number of moles of water in 338 mL.
Molar mass of water = 18 g/mole
Formula for number of moles = mass/molar mass.
Mass = density × volume = 0.0992 × 338 = 33.5296 g
Thus;
Number of moles = 33.5296/18 = 1.863 moles.
Let's use the same procedure to find the Number of moles of glycerine.
Molar mass of glycerine from online values = 92.1 g/mol
Thus;
n_glycerine = (mass)/92.1
We have mass and density as 164 g and 0.0992 g/cm³ respectively.
n_glycerine = 164/92.1
n_glycerine = 1.78
Total moles of solution = 1.863 + 1.78 = 3.643 moles
We are told that The vapor pressure of pure water at 39.8°C is 54.74 torr
Thus, since water dominates, then vapour pressure of solution = (1.863/3.643) × 54.74 ≈ 28 torr
convert 256 ml to kl
Answer:
0.000256
Explanation:
Formula:
Divide the value volume by 1e+6
1 kl equal to 1000000ml
what would happen if you boil a substance in an alcohol
Answer:
When a mixture of water and alcohol boils, the vapors are a mixture of water vapor and alcohol vapor
ionisation potential of the element increases across a period from left to right
Answer:
False
Explanation:
It actually decreases.
Q2.
This question is about metals and metal compounds.
(a)
Copper oxide reacts with hydrochloric acid to produce copper chloride and water.
Copper oxide is insoluble in water.
Copper oxide is gradually added to hydrochloric acid until in excess.
Magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen.
Plan an investigation to find the accurate volume of hydrogen produced from
magnesium
You do not need to write about safety precautions.
Answer:
sry I don't know the answer
10:38 Fri 9 Jul
ES
GCSE Science - Chemistry
2 of 15
Name the indicator that is red in acid and turns green when the solution becomes neutral.
|
Answer.
Universal indicator
Explanation.
Universal indicator has many different colour changes, from red for strongly acidic solutions to dark purple for strongly alkaline solutions. In the middle, neutral pH 7 is indicated by green.
what is 10x412x3021x13123
A solution of known concentration is called
Answer:
It is called standard solution.
Explanation:
I hope this helps! Have a nice dayy! :)
what is the wave speed
a wave with a wave length of 1000 m and a frequancy of 3000000 Hz
Answer:
v = 3,000,000,000 m/s
Explanation:
v = f *L
v = 3,000,000 * 1000
v = 3,000,000,000 m/s
Balance equation for. _Mg + _H3(PO4) --_Mg3(PO4)2+ _H2
Stoichiometry - Chemistry
Answer:
C
Explanation:
in the option C when we rearrange it then it will he C3H6O2
Answer:
yes its C
Explanation:
correct me if iam wrong
The reaction from NaOH and CH3COOH gives
a. Basic Salt
b. Acidic Salt
c. Normal Salt
d. Neutral Salt
How many molecular of H2O and O2 are present in 8.5g of H2O2 ?
2H2O+O2--->2H2O2
8.5 gm H2O2=0.25 mole
hence H2O is also 0.25 mole i.e.4.5 gm
O2is 0.125 mole i.e.4 gm
