If a photon dropping from the n = 7 to the n = 1 level hit the surface of Au, what would be the wavelength of the ejected electron in nanometers?
Answer:
here's the answer.hope it helps
Please help me fill in the blanks
Answer: ew i hate science but ive done that same thing before i dont remember the answers though
Explanation:
How many molecules of H2O are equivalent to 98.2 g of H2O
Answer:
Demo Mole Quantities
58.5g NaCl(mol/58.5g)(6.02 x 1023/mol) = 6.02 x 1023 Na
+
Cl21 pre-1982 pennies (after 1982 pennies are mostly zinc with copper coating)
63.5g Cu( mol/ 63.5g)(6.02 x 1023/mol) = 6.02 x 1023 Cu
19.0g Al (mol/27.0g)(6.02 x 1023/mol) = 4.24 x 1023 Al
Explanation:
CaCO3 (s) + 176 KJ à CaO (s) + CO (g)
A. 176 KJ are released in an endothermic reaction.
B. 176 KJ are released in an exothermic reaction
C. 176 KJ are absorbed in an exothermic reaction.
D. 176 KJ are absorbed in an endothermic reaction.
Answer:
its d
Explanation:
The Sun is located _____.
in the central core of the Milky Way galaxy
in the bar of the Milky Way
in an arm about 25% of the distance from the center of the Milky Way to its outer edge
in an arm about 75% of the distance from the center of the Milky Way to its outer edge
Answer:
I believe the answer is going to be A. in the central core of the Milky Way galaxy.
Explanation: lol sorry I put it in the question box instead of answering it, hope this helps!
How to solve this problem in Chemistry? I am stuck
The buffer can be made using an acid or a base.
What is a buffer?We have to know that the term buffer is the generic term that can be generally used to describe any solution that is resistant to changes in acidity and the alkalinity of the solution.
We know that we can be able to make a buffer in two ways;
1) By the use of a weak acid and its salt
2) By the use of weak base and its salt.
In each case, the pH of the solution that has been formed would not be easily changed and this is the job of the buffer.
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How many grams of sodium carbonate are produced when 5.3 moles of sodium phosphate reacts with aluminum carbonate?
Answer: There is 842.54 grams of sodium carbonate are produced when 5.3 moles of sodium phosphate reacts with aluminum carbonate.
Explanation:
Chemical equation depicting reaction between sodium phosphate and aluminum carbonate is as follows.
[tex]Al_{2}(CO_{3})_{3} + 2Na_{3}PO_{4} \rightarrow 2AlPO_{4} + 3Na_{2}CO_{3}[/tex]
As this equation contains same number of atoms on both reactant and product side. So, this equation is a balanced equation.
According to the equation, 2 moles of sodium phosphate is giving 3 moles of sodium carbonate.
Therefore, sodium carbonate formed by 5.3 moles of sodium phosphate is as follows.
[tex]\frac{3}{2} \times 5.3 mol\\= 7.95 mol[/tex]
As number of moles is the mass of substance divided by its molar mass. So, mass of sodium carbonate ( molar mass = 105.98 g/mol) is as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\7.95 mol = \frac{mass}{105.98 g/mol}\\mass = 842.54 g[/tex]
Thus, we can conclude that there is 842.54 grams of sodium carbonate are produced when 5.3 moles of sodium phosphate reacts with aluminum carbonate.
Balance the following Equation (do not leave any empty blanks, you must enter 1 if the value is 1):
___ Na2S + ___ HCl --> ___ NaCl + ___ H2S
(Refer to image)
What type of reaction is it?
(Question one is a _______ type of reaction.)
Answer: this looks hard
Explanation:
Answer:
1 Na2S + 2 HCl ===> 2 NaCl + 1 H2S
In these reactions, two compounds exchange ions to form two new compounds.
Explanation:
--- Na2S + ---- HCl ===> ---- NaCl + ---- H2S
Na = 2 Na = 1 * 2 = 2
S = 1 S = 1
H = 1 * 2 = 2 H = 2
Cl = 1 * 2 = 2 Cl = 1 * 2 = Cl
In these reactions, two compounds exchange ions to form two new compounds.
REACTION TYPE:
DOUBLE DISPLACEMENT REACTION/DOUBLE REPLACEMENT
I hope that helps, have a wonderful day!!!!
Each of the following sets of quantum numbers is supposed to specify an orbital Choose the one set of quantum numbers that does NOT contain an error.
a) n=4, I=4, m/=1
b) n=5, I=3, m/=- 3
c) n=3, I=1, m/= -2
d) n=3, I= 2, m/=+3
Answer:
C
Explanation:
The correct answer is C because the first quantum numbers containing and encompass in an orbital m contain a definite she'll of 2 and hence
Which phase change results in atoms with the highest kinetic energy? A. Boiling B. Melting C. Freezing D. Condensing
Answer: Boiling because it makes the molecules in water bounce around.
Hope it helps.
WILL MARK BRAINLIEST!!
Which situation indicates a beta emission?
The atomic number increases by one, but the mass number does not change.
The atomic number decreases by two, and the mass number decreases by four.
The atomic number decreases by one, and the mass number decreases by one.
The atomic number and the mass number both decrease by two.
Answer:
A: The atomic number increases by one, but the mass number does not change.
Please show all of your work, I need to understand all steps:
A student collected time (t) and concentration ([A]) data at
295 K for the reaction 2A→B. These time and concentration data are shown in the table to the right. The student then plotted graphs of [A] versus t (Figure 1) , ln[A] versus t (Figure 2) , and 1/[A] versus t (Figure 3) .
Figure 1:
t (s) (A)(M) ln(A) 1/ (A)
0.00 0.500 −0.693 2.00
20.0 0.389 −0.944 2.57
40.0 0.303 −1.19 3.30
60.0 0.236 −1.44 4.24
80.0 0.184 −1.69 5.43
i.) What is the rate of the reaction?
ii.) What is the value of the rate constant for this reaction?
iii.)
Next, the student ran the same reaction at a different temperature and measured a different reaction rate, with the following results:
T(K) k(s-1)
295 0.0125
325 0.0357
What is the activation energy of this reaction?
Express your answer to three significant figures and include the appropriate units.
Answer:
a because the x and y value is the same
PLEASE HELP 15 POINTS!! Which equation is needed to solve this problem?
Answer:
Option 1
Explanation:
The question is asking us what formula is used to obtain the quantity of heat added to a given mass of mercury in order to cause its temperature to change.
This quantity of heat is obtained from;
q = mcspΔT
Where;
q = quantity of heat added
m = mass of the mercury
csp= specific heat capacity of mercury
ΔT = temperature change
Anyone know this
Please help me
Answer:
sorry I don't know
Explanation:
have a great time with your family and friends
10 points
Scenario: Calculate the new temperature when a 2.0 L of a gas at 220 K is compressed to 1.0 L.
Hint! You should check three boxes: one to describe particle speed, one to describe particle spacing and one to describe number of particle collisions.
Question 5 options:
The particles speed up.
The particles slow down.
The particle speed doesn't change.
The particles get squished (compressed) together.
The particles float farther apart.
The distance between particles doesn't change.
The amount of collisions among particles in the gas sample increase.
The amount of collisions among particles in the gas sample decrease.
The amount of collisions among particles in the gas sample doesn't change.
Answer:
The 2nd, 4th, and 7th options
Explanation:
The density of oxygen gas at a certain temperature and pressure is 1.345 g cm-3. How many oxygen atoms are present in 2.0 L of oxygen gas at this same temperature and pressure?
The number of oxygen atoms present in 2.0L of oxygen gas at same temperature and pressure is 5.1 × 10²² atoms.
How to calculate number of atoms?The number of atoms of a substance can be calculated by multiplying the number of moles in the substance by Avogadro's number (6.02 × 10²³).
no of atoms = no of moles × 6.02 × 10²³
According to this question, the density of oxygen gas at a certain temperature and pressure is 1.345 g cm-³. If 2.0 L of oxygen gas is given, the mass of the oxygen gas can be calculated as follows:
mass = 1.345 × 2 = 2.69grams
moles = 2.69g ÷ 32g/mol = 0.084moles
No of atoms = 0.084 mol × 6.02 × 10²³
no of atoms = 5.1 × 10²² atoms
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5. (a-c) In the balanced equation below, how many grams of solid iron can be formed if 50.0g Fe2O3 reacts with 10.0g of CO?
Fe2O3(s) + 3CO(g) → 2Fe(s) +3CO2
a. What mass of the excess reactant remains after the reaction occurred?
b. If you conducted an experiment and 11.5 grams of Fe(s) was formed what would be the percent yield?
c. If the percent yield for the process to obtain 75 kg of CO2 was 80.7%, how many kg of CO is needed?
From the balanced equation of the reaction, the mole ratio of the reactants is 1:3.
Mole of 50.0 g [tex]Fe_2O_3[/tex] = 50/160 = 0.3125 mol
Mole of 10.0 g CO = 10/28 = 0.3571 mol
Stoichiometric equivalent of [tex]Fe_2O_3[/tex] = 0.3571/3 = 0.1190 mol
In other words, [tex]Fe_2O_3[/tex] is in excess.
Excess mole = 0.3125 - 0.1190 = 0.1935 mol
Mass of 0.1935 mol [tex]Fe_2O_3[/tex] = 0.1935 x 160 = 30.96 grams
Mole ratio of CO to Fe = 3:2
Equivalent mole of Fe that would be formed = 0.3571 x 2/3
= 0.2381 mol
Mass of 0.238 mol Fe = 0.238 x 56 = 13.328 grams
Percent yield of Fe = 11.5/13.328 x 100 = 86.28%
Mole of 75 gk CO2 = 75000/44 = 1704.55 mol
Mole ratio of CO2 and Co = 1:1
Equivalent mole of CO = 1704.55 mol
Mass of 1704.55 mol CO = 1704.55 x 28 = 47.73 kg
80.7% = 47.73 kg
100% = 100 x 47.73/80.7
= 59.14 kg
In other words, 59.14 kg of CO would be needed.
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I need help please in this:(
Answer:
That would be A sir or Miss
Explanation: Tell me if I am wrong, Also hope this helped you!
4. A student poured 50 cm^3
water into a beaker and
measured the water's
temperature. The student added
1.00 g calcium chloride to the
water, stirred the mixture and
then recorded the temperature.
The concentration of a calcium
chloride solution is 12 g/dm^3.
Calculate the volume of this
solution, in cm^3, that contains
9.0 g of calcium chloride.
Answer:
V = 750 cm³
Explanation:
The volume of the solution can be calculated by the following formula:
[tex]V = \frac{M}{C}[/tex]
where,
V = Volume of solution = ?
M = Mass of Calcium Chloride = 9 g
C = Concentration of Solution = 12 g/dm³
Therefore,
[tex]V = \frac{9\ g}{12\ g/dm^3}\\\\V = (0.75 dm^3)(\frac{1000\ cm^3}{1\ dm^3})[/tex]
V = 750 cm³
We learned that Energy can
exist in many forms.
Do you think energy can
converted from one form to
another?
How many moles of magnesium atoms react with 1 mole of oxygen molecules?
1 mole of magnesium atoms will react with 2 moles of oxygen molecules. This is because the chemical equation for the reaction between magnesium and oxygen is: Mg + O2 → MgO.
What is chemical equation?A chemical equation is a symbolic representation of a chemical reaction, showing the reactants (starting materials) on the left side and the products (resulting substances) on the right side. The symbols used to represent the reactants and products are chemical formulas, which use the symbols of the elements in the reaction. The arrow between the reactants and products indicates the type of reaction taking place. The coefficients next to the symbols and formulae of entities indicate the number of moles of each species that are involved in the reaction. The overall reaction is balanced when the number of atoms of each element on the left side of the equation is equal to the number of atoms of that element on the right side of the equation.
This equation shows that for every 1 mole of magnesium atoms, 2 moles of oxygen molecules are required for the reaction to take place. Therefore, 1 mole of magnesium atoms will react with 2 moles of oxygen molecules.
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9. a) What is an isotope?
Answer:
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element. Hope this helps, have a good day! :)
Answer:
atoms with the same number of protons and electrons but different numbers of neutrons
Explanation:
what is the energy of a photon of yellow light with a frequency of 5.2 x 10¹⁴ Hz?
Answer:
3.4x10⁻¹⁹J is the energy of the photon
Explanation:
To find the energy of a photon from its frequency we must use the equation:
E = hf
Where E is the energy of the photon in J, our incognite
h is Planck's constant = 6.6262x10⁻³⁴Js
And f is the frequency = 5.2x10¹⁴Hz = 5.2x10¹⁴s⁻¹
Replacing:
E = 6.6262x10⁻³⁴Js*5.2x10¹⁴s⁻¹
E = 3.4x10⁻¹⁹J is the energy of the photon
Why does the standard model of the universe need to be change?
Explanation:
The standard model of particle physics is a relativistic theory of quantum fields developed between 1970 and 1973 [citation needed] based on the ideas of unification and symmetries [1] that describes the fundamental structure of matter and vacuum considering the elementary particles as irreducible entities whose kinematics is governed by the four known fundamental interactions (except for gravity, whose main theory, general relativity, does not fit the mathematical models of the quantum world). The word "model" in the name comes from the 1970s when there was not enough experimental evidence to confirm the model. [1] To date, almost all experimental tests of the three forces described by the standard model are in agreement. with their predictions. However, the standard model falls short of being a complete theory of fundamental interactions due to several unresolved issues.
The form of energy carried by moving electrical charges is ____________________ energy.
Answer:
kinetic
Explanation:
hope this helps
Answer:
Kinetic energy
Explanation:
A 752g sample of an unknown substance has its temperature increase by 8°C after being exposed to 1287.424 j,calculate the specific heat of
the substance. _____J/g*C (3 sig figs)
Answer:
0.214 J/g.°C
Explanation:
Step 1: Given data
Mass of the sample (m): 752 gTemperature increase (ΔT): 8 °CProvided heat (Q): 1287.424 JStep 2: Calculate the specific heat of the substance (c)
The specific heat of the substance is an intrinsic property of a substance. We can calculate it using the following expression.
Q = c × m × ΔT
c = Q / m × ΔT
c = 1287.424 J / 752 g × 8 °C = 0.214 J/g.°C
Starting with 2.50 mol of N2 gas (assumed to be ideal) in a cylinder at 1.00 atm and 20.0C, a chemist first heats the gas at constant volume, adding 1.36 * 104 J of heat, then continues heating and allows the gas to expand at constant pressure to twice its original volume. Calculate (a) the final temperature of the gas; (b) the amount of work done by the gas; (c) the amount of heat added to the gas while it was expanding; (d) the change in internal energy of the gas for the whole process.
Answer:
a) [tex]T_b=590.775k[/tex]
b) [tex]W_t=1.08*10^4J[/tex]
d) [tex]Q=3.778*10^4J[/tex]
d) [tex]\triangle V=4.058*10^4J[/tex]
Explanation:
From the question we are told that:
Moles of N2 [tex]n=2.50[/tex]
Atmospheric pressure [tex]P=100atm[/tex]
Temperature [tex]t=20 \textdegree C[/tex]
[tex]t = 20+273[/tex]
[tex]t = 293k[/tex]
Initial heat [tex]Q=1.36 * 10^4 J[/tex]
a)
Generally the equation for change in temperature is mathematically given by
[tex]\triangle T=\frac{Q}{N*C_v}[/tex]
Where
[tex]C_v=Heat\ Capacity \approx 20.76 J/mol/K[/tex]
[tex]T_b-T_a=\frac{1.36 * 10^4 J}{2.5*20.76 }[/tex]
[tex]T_b-293k=297.775[/tex]
[tex]T_b=590.775k[/tex]
b)
Generally the equation for ideal gas is mathematically given by
[tex]PV=nRT[/tex]
For v double
[tex]T_c=2*590.775k[/tex]
[tex]T_c=1181.55k[/tex]
Therefore
[tex]PV=Wbc[/tex]
[tex]Wbc=(2.20)(8.314)(1181_590.778)[/tex]
[tex]Wbc=10805.7J[/tex]
Total Work-done [tex]W_t[/tex]
[tex]W_t=Wab+Wbc[/tex]
[tex]W_t=0+1.08*10^4[/tex]
[tex]W_t=1.08*10^4J[/tex]
c)
Generally the equation for amount of heat added is mathematically given by
[tex]Q=nC_p\triangle T[/tex]
[tex]Q=2.20*2907*(1181.55-590.775)\\[/tex]
[tex]Q=3.778*10^4J[/tex]
d)
Generally the equation for change in internal energy of the gas is mathematically given by
[tex]\triangle V=nC_v \triangle T[/tex]
[tex]\triangle V=2.20*20.76*(1181.55-293)k[/tex]
[tex]\triangle V=4.058*10^4J[/tex]
A sample of 4.0 L of nitrogen, at 1.2 atmospheres, is transferred to a 12 L container.
What will the pressure be in the new container?
Answer:
The pressure will be 0.4 atm.
Explanation:
The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system. The parameters evaluated in these laws are pressure, volume, temperature and moles.
As the volume increases, the gas particles (atoms or molecules) take longer to reach the walls of the container and therefore collide with them less times per unit of time. This means that the pressure will be lower because it represents the frequency of collisions of the gas against the walls. In this way pressure and volume are related, determining Boyle's law which says:
"The volume occupied by a certain gaseous mass at constant temperature is inversely proportional to pressure"
Boyle's law is expressed mathematically as:
P*V= k
If you initially have the gas at a volume V1 and press P1, when the conditions change to a volume V2 and pressure P2, the following is satisfied:
P1*V1= P2*V2
In this case:
P1= 1.2 atmV1= 4 LP2= ?V2= 12 LReplacing:
1.2 atm* 4 L= P2* 12 L
Solving:
[tex]P2=\frac{1.2 atm*4 L}{12 L}[/tex]
P2= 0.4 atm
The pressure will be 0.4 atm.
What is the molecular weight of MgCl2
The molecular weight of MgCl₂ is 94 g/mol.
What is molecular weight?This refers to the total mass of a compound. It is equivalent to the sum of the individual atomic masses of each atom in the molecule.
Steps to determine the molecular formula of the molecule.
Determine the atomic mass of each element in the molecule.Multiply each element's atomic mass by the number of atoms of that element in the molecule. This number is represented by the subscript next to the element symbol in the molecular formula.Add these values together for each different atom in the molecule.The total will be the molecular mass of the compound.Atomic number of Cl =17
Atomic number of Mg = 12
Mass number of Cl = 35
Mass number of Mg = 24
Calculating the molecular weight of MgCl₂
MgCl₂
=(12* 2) + (35*2)
= 24 + 70
= 94 g/mol.
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Why atoms form compounds
Answer:
Because the atoms are trying to reach the most stable ( lowest energy ) state they can.