If an electron falls from the n = 2 to the n = 1 energy levels in a Hydrogen atom what wavelength of light is emitted?
Answer:
Ultraviolet
Explanation:
It doesn't use much energy and so it creates ultraviolet light.
which subatomic particle made out of protons neutrons and electrons can charge and still be considered the same element
Answer:
Proton
Explanation:
which statement best describes what happens during mitosis
Answer:
Osmosis is a process which occurs when there is a difference in solute concentration between two solutions separated by a semipermeable membrane. A semipermeable membrane allows passage of water but not of solutes. The passage of water occurs because of a pressure difference of water between the two solutions
When discussing distances between the solar system, which term do we use
A. Actual distance
B. Relative Brightness
D. Realtive distance
If its right you get brainless
I'm in 5th grade
wich of the following solute and solventis not belong to suspension mixture
A.sticky, creamy subtances
B.clear, pure subtances
C.dark, black subtances
D.clear, flowless sunbtances
b is your best bet hope this helps
Ques. A uniform cylinder of mass 4.3 kg and radius 0.4 m rolls down a ramp inclined at an angle 0.15 radians to the horizontal. What is the acceleration of the cylinder in m/s2 ?
The acceleration of the cylinder in m/s2 is 0.973 meters per seconds squared.
What is acceleration?Acceleration is the change of velocity with time. The unit is usually meters per seconds squared.
mass = 4.3 kg
radius = 0.4m
angle of inclination, ∅ = 0.15 radians
How to solve acceleration of the cylinder in m/s^2acceleration of the cylinder in m/s^2
= ( g + sin ∅ ) / 1 + 0.5
= ( 9.81 + sin 0.15 ) / 1.5
take note angle is in radians not degrees
= 1.46 / 1.5
= 0.973 meters per seconds squared
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Which of the following are kept as a constant in Boyle's law (check all that
apply)
volume
temperature
amount
pressure
none of these
Answer:
temperature
amount
Explanation:
Under the postulate of Boyle's law, both temperature and amount(number of moles) are kept constant.
According to Boyle's law "the volume of a fixed mass of gas varies inversely as the pressure changes if the temperature is constant"
Based on the premise of this law, both temperature and amount of substance is kept constant.
How much sulphuric acid containing 80% H2SO4 by weight is needed to produce 500 kg of 80% HCL by weight 2NaCl+ H2SO4--------Na2SO4 + 2HCl
In the given question, the sulphuric acid which is needed to be produced is 408.333 Litres. NaCl + H₂SO₄ → HCl + NaHSO₄
This question is based on stoichiometry, in which we first balance the equation, equate the moles or the masses of elements and using the mole ratio or mass ratio, find the given amount of weight or moles of the desired element from the reaction. Stoichiometry helps us to predict the reaction components that how much it participates in the reaction, how much we the get the product or how much reactant is left. So, in the given question,
Equating the Molar masses: 58 + 98 → 36 + 120. Mass of HCl =[tex]500*0.8= 400[/tex] kg. Balancing the mass:
[tex]400[(58/120)+(98/120)][/tex] → [tex]400[(36/120)+(120/120)][/tex]
Volume of H₂SO₄ 80% = [tex]400 * (98/120)] /0.8= 408.333[/tex]
The final answer is 408.333 Litres. This was solved using Stoichiometry.
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List 3 properties of the hair’s cuticle.
Zn(s) + 2HCl(aq) > H2(g) + ZnCl2 (aq)
When 25.0g of Zn reacts, how many mols of HCl are consumed?
A. 0.0171 B. 1.5 C. 0.76 D. 22.4 E. 0.38
When 25.0g of Zn reacts, mols of HCl are consumed 0.7648 moles HCl
Write down the balanced chemical equation for this one replacement reaction first.
Zn(s)+2HCl(aq)→ZnCl2(aq)+H2(g)↑⏐
Now take note of the 2:1 mole ratio of reaction between the two reactants. This demonstrates that the reaction will always use up two times as much hydrochloric acid as zinc metal.
As you are aware, a solution's molarity indicates the number of moles of solute—in your case, hydrochloric acid, HCl—that are present in one liter of the solution.
The molarity of the hydrochloric acid solution is reported to be
3.05 mol L−1. This indicates that for every 1 L of solution, 3.05 moles of hydrochloric acid are produced. Remember this for later. You are aware that the reaction needs 25.0 g of zinc.
By using the molar mass of zinc, you can convert this mass to moles.
25 g per mole Zn
65.38g = 3.824 moles of zinc
n order for this many moles of zinc to react, you'd need
0.3824moles Zn⋅2amoles
HCl 1 mole Zn=0.7648 moles HCl
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How many moles of sulfur dioxide (SO2) are required to produce 5.0 moles of sulfur (S) according to the following balanced equation? SO2 + 2H2S - 3S + 2H2O
Answer:
1.67 moles
Explanation:
From the balanced equation of reaction:
[tex]SO_2 + 2H_2S -> 3S + 2H_2O[/tex]
1 mole of sulfur dioxide, SO2, is required to produce 3 moles of sulfur, S.
If 1 mole SO2 = 3 moles S, then, how many moles of SO2 would be required for 5 moles S?
Moles of SO2 needed = 5 x 1/3
= 5/3 or 1.67 moles
Hence, 1.67 moles of SO2 would be required to produce 5.0 moles of S.
Answer: 1.7
Explanation:
What is the mass number of an atom that consists of 20 protons, 20 neutrons, and 18 electrons?
Answer:
C)a mass number of 38
Explanation:
yes
Pb in tetraethyl lead, Pb(C2H5)4 (once extensively used as an additive to gasoline to prevent engine knocking)
Express your answer using four significant figures. Determine the percent,by mass, for Pb
The percent mass of lead in tetraethyl lead is 64.1%.
What is the percent by mass of Pb in tetraethyl lead, Pb(C₂H₅)₄?The percent by mass of an element in a compound is determined by taking the ratio of the atomic mass of the element and the molar mass of the compound and then multiply by 100%
Percent mass = (atomic mass of element/molar mass of compound) * 100%atomic mass of Pb = 207
atomic mass of C = 12
atomic mass of H = 1
Molar mass of tetraethyl lead: 207 + 12 * 2 * 4 + 1 * 5 * 4
Molar mass of tetraethyl lead = 323 g/mol
Percent mass of Pb = 207/323 × 100%
Percent mass of Pb = 0.6408 × 100%
Percent mass of Pb = 64.1%
In conclusion, the percent mass of lead in tetraethyl lead is 64.1%.
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What is the empirical formula for a compound that has 57.5%
Na, 40.0% 0, and 2.5% H?
a
Naz(OH)4
b
Na(OH)2
С
Na(OH)
d
Naz(OH)
Answer:
c
Explanation:
use %composition given to calculate emperical 4mular
The empirical formula of the compound having 57.5% Na, 40.0% O, and 2.5% H is NaOH (Option C)
Data obtained from the questionNa = 57.5%O = 40%H = 2.5%Empirical formula =?How to determine the empirical formulaDivide by their molar mass
Na = 57.5 / 23 = 2.5
O = 40 / 16 = 2.5
H = 2.5 / 1 = 2.6
Divide by the smallest
Na = 2.5 / 2.5 = 1
O = 2.5 / 2.5 = 1
H = 2.5 / 2.5 = 1
Thus, the empirical formula of the compound is NaOH
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HELPPPP give me an example of thermal energy and describe what is happening at particle level.
Answer:
Thermal energy (also called heat energy) is produced when a rise in temperature causes atoms and molecules to move faster and collide with each other. The energy that comes from the temperature of the heated substance is called thermal energy.
Explanation:
will this help you
A neutral atom of Cl-37 has
O 37 protons, 37 neutrons, and 37 electrons O 17 protons, 37 neutrons, and 17 electrons 17 protons, 20 neutrons, and 37 electrons 17 protons, 20 neutrons, and 17 electrons
Answer:
17 protons, 20 neutrons, and 17 electrons.
Explanation:
A periodic table can be defined as the standard arrangement of chemical elements by atomic number, electronic configuration and chemical properties in a tabular form.
Generally, a proper representation of the mass number and atomic number of chemical elements is key and very important in chemistry.
Furthermore, as a rule, it should be noted that the mass number (nucleon number) is always larger than the atomic number(number of proton).
The mass number of this neutral atom of Cl-37 is 37 and we know that the atomic number (number of protons) of chlorine is 17. Also, the atomic number of an element is equal to the number of its electrons.
A neutral atom of Cl-37 has 17 protons, 20 neutrons, and 17 electrons.
Hence, a neutral atom of Cl-37 can be identified based on its number of protons because it represent its atomic number, which is what is used to differentiate an atom of an element from the atom of another chemical element.
A 10.0-g sample of sodium chloride was placed in 10.0 g of water. If 3.85 g of Cl2 was obtained, what was the percent yield of Cl2
Answer:
63.53% yield
Explanation:
The balanced equation for this reaction is 2NaCl + H2O -> 2NaOH +Cl2
First we must find the limiting reactant
From NaCl we can only produce 6.06 grams of Cl2 in theory
From H20 we can only produce 38.995 grams in theory
so we know NaCl is the limiting
% yield is (Actual/Theoretical) x100 so
(3.85/6.06)x100= 63.53% yield
If the pH of a certain solution changes from 8 to 9, what happens to the hydrogen ion concentration
The concentration of OH⁻ ions will become 10 times the initial concentration.
What is indicated by the hydrogen ion concentration?A more useful approach to express the concentration of hydrogen ions is on the pH scale, which is the logarithm of the reciprocal of the hydrogen ion concentration in gram moles per liter. The concentrations of the hydrogen ion (H+) and the hydroxyl ion (OH) are both equal to 10⁻⁷ in a neutral solution. The pH of seven is neutral.
Solution pH 1 equals 8.
Solution's pH is 2 = 9.
pOH₁ = 14 - 8 = 6
pOH₂ = 14 - 9 = 5
OH₁⁻ = 10⁻⁶
OH₂⁻ = 10⁻⁵
Ratio = 10⁻⁵ / 10⁻⁶ = 10
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Which gas law is represented by the following equation: V1/T1 = V2/T2
1 point
Gay-Lussac's law
Boyle's law
Avogadro's law
none of these
Charles's law
Answer:
Charles's law
Explanation:
The chemical equation given is that of Charles's law;
The law states that "the volume of a fixed mass of a gas varies directly as its absolute temperature if the pressure is constant"
mathematically;
v ∝ T ( P, n constant)
So;
V1/T1 = V2/T2
V and T are volume and temperature values
1 and 2 are initial and final states
A 1599 kg car is traveling down the road at 83.4 km/h. While traveling at this rate of speed, what is the kinetic energy of this vehicle in kilojoules?
Ek=
A 56.87 g sample of a substance is initially at 30.0 °C. After absorbing 1475 J of heat, the temperature of the substance is 138.4 °C. What is the specific heat ( ) of the substance?
c=
The kinetic energy of 429 kJ and the specific heat of the substance is 9059 g kJ °C
The kinetic energy is given as ,
K.E = 1/2 m[tex]v^{2}[/tex]
Where m = mass = 1599 kg
v = velocity = 83.4 km/h = 23 m/s
Putting the value mass and velocity in equation ( i ) we get ,
K.E = 1/2 × 1599 kg × 23 m/s × 23 m/s = 429074.86 J = 429 kJ
Specific heat is calculated as ,
Q = mcΔT
mass of the substance ( m ) = 56.87 g
c = 1475 J
ΔT = 138.4 °C - 30.0 °C = 108 °C.
Putting the value of mass , change in temperature and heat absorbed in equation ( ii ) we get ,
Q = 56.87 g × 1475 J × 108 °C = 9059391 gJ°C = 9059 g kJ °C
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how to know if a guy is really into you?
What is the mass of 3.99 mol of nickel?
Answer:
234.213
Explanation:
Moles of Nickel x 58.70 = Grams
3.99 x 58.70 = 234.213
The density of silver is 10.5 g/cm³. A students performs three trials of an experiment and obtains the
following results: 14.2 g/cm³, 14.0 g/cm³, and 7.25 g/cm³. Are these results accurate? Explain. Are the
results precise? Explain.
Results are neither precised nor accurate.
In the Given Actual density of silver =10.5 g / cm^3
Measured values of silver density = 14.2 g/cm^3
14.0g/cm^3
7.25g/cm^3
We have to find whether the measurements given are accurate or precise.
so , Density can be defined as the ratio of mass to volume. The formula for calculation of density is shown below :
Density = Mass / Volume
The units of density is generally g / ml.
The results are said to be accurate if our measured value exactly matches with our true value.
In case of precision ,all the measured values should be near to each other or should differ only by 0.1 or 0.2.
So in this case the measured values are not precised nor accurate because it does not matches with true value also.
Hence , the results are neither precised nor accurate.
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13. When pentane undergoes complete combustion, the products are carbon dioxide and water.
C5H12
+ 02 →
CO2 +
H20
What are the respective coefficients when the equation is balanced with the smallest whole numbers?
a. 1,5, 3, 4
b. 2, 6, 5, 6
c. 1, 8, 5,6
d. 2, 16, 10, 12
Answer:
i think c
Explanation:
:D
The term "cycle" is used in Water Cycle because ?
Answer:
because cycle is a prosess that goes through multiple stages
Explanation:
.
Calcium carbonate is a white mineral. A chemist heats calcium carbonate, CaCO3, to produce carbon dioxide, CO2, and a white powder, CaO. The following chemical equation shows the reaction.CaCO3 → CO2 + CaO Explain why the products have different properties than the reactants
Answer:
A chemical change has occurred
Explanation:
Given reaction expression:
CaCO₃ → CaO + CO₂
The reaction is a decomposition reaction in which a compound is dissociated into simple products.
The reason why the products have different properties than the reactants is because a chemical change has occurred.
A chemical change is accompanied by the formation of a new productSuch new products have different properties compared to the compound that forms them. Therefore, the products and reactants are different chemically due to chemical change that has occurred.The products of the decomposition of calcium carbonate have different properties because a chemical change has occured in the reaction to form new substances.
CHEMICAL CHANGE:A chemical change is a type of change in which new products are formed. The bonds of the reactants are broken and rearranged to form entirely new substances. According to this question, calcium carbonate is a white mineral, which when heated produces carbon dioxide, CO2, and a white powder, CaO as follows: CaCO3 → CO2 + CaOThe products in this reaction are different in their properties from the reactants because a chemical change has caused new substances to be formed.Learn more about chemical change at: https://brainly.com/question/1161517?referrer=searchResults
what are the answers easily!!!!
Answer:
True
True
Temperature
Explanation:
PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP!!
DUE IN 10 MINS
Number 9 and 10!
Answer:
the answer is your a awesome person
why is the cell wall so important to the plant cell???
Explanation:
Cellulose fibers, structural proteins, and other polysaccharides help to maintain the shape and form of the cell. Additional functions of the cell wall include: Support: The cell wall provides mechanical strength and support. It also controls the direction of cell growth.
Make the following conversion.
954 g= _ kg
0954000
95400
0.954
0.0954
Answer:
0.954
Explanation:
1000 grams is 1 kg
954 grams is 954/1000 kg or 0.954