Hello!!
Who was Neil Bohr?
Explain the theory he introduced.
Answer:
In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values. Electrons move around a nucleus, but only in prescribed orbits, and if electrons jump to a lower-energy orbit, the difference is sent out as radiation.
I showed maturity when I
I showed maturity when I turn 13 year old
What mass of Ca(OH)2 must be dissolved in 0.504 L of a solution to make a 0.56 M solution?
0.28 g
21 g
1.1 g
0.90 g
20.91200832 g of [tex]Ca(OH)_{2}[/tex] must be dissolved in 0.504 L of a solution to make a 0.56 M solution.
What is the molarity of a solution?
Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution. Molarity is also known as the molar concentration of a solution.
[tex]Molarity = \frac{Mole \;of \;solute}{Volume \;of \;solution \;in \;litre}[/tex]
Given data:
The volume of solution= 0.504 L
Molarity of [tex]Ca(OH)_{2}[/tex] = 0.56 M
Step 1: Calculating the mass of [tex]Ca(OH)_{2}[/tex]
Putting the given values in the equation.
[tex]Molarity = \frac{Mole \;of \;solute}{Volume \;of \;solution \;in \;litre}[/tex]
[tex]0.56 M = \frac{Mole \;of \;solute}{0.504 L }[/tex]
Moles of solute = 0.28224
[tex]Moles \;of \;solute= \frac{Given \;mass}{Molar \;mass}[/tex]
Molar mass of [tex]Ca(OH)_{2}[/tex] = 74.093 g/mol
Now, put the values in the formula.
[tex]Moles \;of \;solute= \frac{Given \;mass}{Molar \;mass}[/tex]
[tex]0.28224 mol= \frac{Given \;mass}{74.093 g/mol}[/tex]
Mass of [tex]Ca(OH)_{2}[/tex] =20.91200832 g
Hence, 20.91200832 g of [tex]Ca(OH)_{2}[/tex] must be dissolved in 0.504 L of a solution to make a 0.56 M solution.
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Oxidation state of Nitrogen in N2O5
Explanation:
Oxidation state of Nitrogen in N2O5 is +5
how many elements are in a Sulfur dioxide
Please help me im begging
Which sentence best describes the shapes of the moon over the course of about a month? (2 points)
Group of answer choices
Over the course of about a month, the shape of the moon does not change.
Over the course of about a month, the shape of the moon changes from a crescent, to a half circle, to three quarters of a circle, to a full circle.
Over the course of about a month, the shape of the moon changes from a crescent, to a full circle, to a half circle, and finally to three quarters of a circle.
Over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
The sentence best describes the shapes of the moon over the course of about a month is over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
What is full moon?The moon when looks like a full circle and having the highest brightness over its life cycle is called the full moon.
The full moon, crescent, half moon or no moon are all the stages of a Moon's lifecycle.
Over a period of 14 days, moon changes from a full moon to no moon. In the another 14 days, no moon changes to full moon. This cycle keeps on going for years and years.
Thus, the sentence best describes the shapes of the moon over the course of about a month is over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
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Answer:
Over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
Explanation:
Sodium hydroxide reacts with sulfuric acid according to the equation:
NaOH + H2SO4 + Na2SO4 + H2O
27. Name this type of reaction:
28. Balance the chemical equation:
Answer:
27) Double replacement
28) 2NaOH + H2SO4 --> Na2SO4 + 2H2O
Your vocal cords act like a guitar string. True or false and why
Answer:
True
Explanation:
Vocal folds vibrate when excited by aerodynamic phenomena; they are not plucked like a guitar string. Air pressure from the lungs controls the open phase. The passing air column creates a trailing “Bernoulli effect,” which controls the close phase.
Answer:
yes
Explanation:
well for some people because some times u can control your voice and sometimes u just get voice cracks
NHCI(s) = NH3(g) + HCl(g) at 427°C, Kp = 4.8. Calculate Kc
[tex]\tt Kp=Kc(RT)^{\Delta n}[/tex]
NH₄Cl (s) ⇔ NH₃ (g) + HCl (g)
Δn = 2 (gas only)
R = 0.082
T = 427 + 273 = 700 K
4.8 = Kc (0.082 x 700)²
Kc = 1.45 x 10⁻³
What is small p value and large p value indicates for
Answer:
P value is commonly used. The prevalent use of P values to summarize the results of research articles could result from the increased quantity and complexity of data in recent scientific research.
Explanation:
Balance the following reaction:
K3PO4 (aq) +
_Ca(OH)2 (aq) →
_Ca3(PO4)2 (s) +
KOH (aq)
Answer:
3 Ca(OH)2 + 2 K3PO4 ---> Ca3(PO4)2 + 6 KOH
Explanation:
Just balance each atom on both sides.
A 0.600-L sample of a 3.75M solution of potassium iodide (KI) contains what mass of KI?
the molarity of a solution made by dissolving 5.67 g of potassium chloride in enough water to make 100.0 mL of solution.
Which soil particle is the smallest, drains water slowly, and holds too much water?
Answer:
Clay
Explanation:
Since Clay has a very small particle size it compacts or has a high surface area which slows the path of water, holding it for longer periods compared to other soil components.
Calculate the number of moles in 5.2g CaCO3
Answer: 0.052moles
Explanation:
number of moles = given mass (g) / molar mass(g/mol)
n=m/M
n= 5.2g/ (40 + 12 + 48)g/mole
n=5.2g/100g/mol
n=0.052 moles
16.
Which chemical reaction will always be spontaneous? (1 point)
an endothermic reaction in which
entropy increases
an exothermic reaction in which
entropy increases
an endothermic reaction in which
entropy decreases
an exothermic reaction in which
entropy decreases
Answer: an exothermic reaction in which entropy increases
Explanation:
Spontaneous reactions normally cause an increase in entropy and are also exothermic.
How much water must be added to 6.0 M silver nitrate in order to make 500 mL of 1.2 M solution?
The amount of water that must be added to 6.0 M silver nitrate to make 500mL of 1.2 M solution is : 2000 mL
Given data :
Concentration of siilver nitrate ( M₁ ) = 6.0 M
volume of solution ( V₁ ) = 500 mL
Conc of solution ( M₂ )= 1.2 M
Determine the amount of water that must be addedwe will apply the equation below
M₁V₁ = M₂V₂ ---- ( 1 )
where : V₂ = V₁ + water added ---- ( 2 )
V₂ ( Final volume ) = ( M₁V₁ ) / M₂
= ( 6 * 500 ) / 1.2
= 2500 mL
Back to eqaution ( 2 )
2500 mL = 500 mL + added water
therefore ; added water = 2500 - 500
= 2000 mL
Hence we can conclude that The amount of water that must be added to 6.0 M silver nitrate to make 500mL of 1.2 M solution is : 2000 mL.
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The specific heat of copper is 0.385 J/gºC. A 95.0 g block of
copper is heated to 77.9°C and placed into a calorimeter that
a
contains 42.0 mL of water at 20.4°C. Assuming no heat loss,
what will be the final temperature of the copper and water?
The final temperature of the copper and water in the calorimeter given the data is 30.3 °C
Data obtained from the questionSpecific heat capacity of copper (C꜀) = 0.385 J/gºCMass of copper (M꜀) = 95 gTemperature of copper (T꜀) = 77.9 °C Mass of water (Mᵥᵥ) = 42 mL = 1 × 42 = 42 gTemperature of water (Tᵥᵥ) = 20.4 °CSpecific heat capacity of the water (Cᵥᵥ) = 4.184 J/gºC Equilibrium temperature (Tₑ) =? How to determine the equilibrium temperatureHeat loss = Heat gain
MᵥᵥC(Tᵥᵥ – Tₑ) = M꜀C(Tₑ – M꜀)
95 × 0.385 (77.9 – Tₑ) = 42 × 4.184(Tₑ – 20.4)
36.575(77.9 – Tₑ) = 175.728(Tₑ – 20.4)
Clear bracket
2849.1925 – 36.575Tₑ = 175.728Tₑ – 3584.8512
Collect like terms
2849.1925 + 3584.8512 = 175.728Tₑ + 36.575Tₑ
6434.0437 = 212.303Tₑ
Divide both side by 212.303
Tₑ = 6434.0437 / 212.303
Tₑ = 30.3 °C
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You just finished your favorite soda which contained 39.0 grams of sugar (C12H22O11). How many molecules of sugar did you ingest?
The number of molecules of sugar, C₁₂H₂₂O₁₁ you ingest given the data is 6.86×10²² molecules
Avogadro's hypothesis1 mole of C₁₂H₂₂O₁₁ = 6.02×10²³ molecules
But
1 mole of C₁₂H₂₂O₁₁ = 342 g
Thus,
342 g of C₁₂H₂₂O₁₁ = 6.02×10²³ molecules
How to determine the molecules in 39 g of sugar342 g of C₁₂H₂₂O₁₁ = 6.02×10²³ molecules
Therefore,
39 g of C₁₂H₂₂O₁₁ = (39 × 6.02×10²³) / 342
39 g of C₁₂H₂₂O₁₁ = 6.86×10²² molecules
Thus, 6.86×10²² molecules are present in 39 g of sugar, C₁₂H₂₂O₁₁
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if the temperature in the gas cylinder shown increases to 30.0°C and the pressure increases to 1.20, will the cylinder's piston move up or down
Answer:
Up
Explanation:
When FeCl2 reacts with K2S, potassium chloride and two compounds are produced. What is the name of the one of the compounds?
Because this is a double replacement reaction, the iron and potassium will swap places, giving [tex]\text{K}_{2}\text{Cl}_{2}[/tex] and [tex]\text{FeS}[/tex].
The names of these compounds are potassium chloride and Iron(II) sulfide
Convert 8.4 kg to grams
Answer:
8,400
Explanation:
multiply 8.4kg by 1000
Answer:
8400g
Explanation:
1kg=1000g
8.4*1000g=8400kg
Which of the following has the most thermal energy? 500 mL water at 25°C 1.5 L water at 25°C 15 L water at 25°C
Answer:
15 L water at 25℃
Explanation:
Answer:
15 L water at 25°C
Question: As the temperature of a substance increases, the average kinetic energy of the particles in the substance
Answer: increases
Explanation:
In an electric toaster, electricity passes through thin metal wires (called filaments) inside the toaster, causing the wires to glow and heat up. The heat given off by the filaments then toasts the bread.
If 500 kilojoules of electricity are supplied to a toaster, which choice below could represent the total amount of heat energy given off by the filaments of the toaster?
A.
480 kilojoules
B.
520 kilojoules
C.
505 kilojoules
D.
630 kilojoules
Answer:
a. 480 kilojoules
Explanation:
good luck have a nice day
what is the coordination number of an atom in FFC unit ?
[tex] \\ [/tex]
ty! :)
Part A Only trace amounts of the synthetic element darmstadtium, atomic number 110, have been obtained. The element is so highly unstable that no observations of its properties have been possible. Based on its position in the periodic table, propose three different reasonable valence electron configurations for this element
Darmstadtium based on its position in the periodic table, proposes three different reasonable valence electron configurations for this element is 2.
What is darmstadtium?Darmstadtium was first synthesized by research scientists at the Heavy Ion Research Laboratory in Darmstadt, Germany in 1994. The element was made by bombarding lead-208 atoms with nickel-62 atoms in a heavy-ion accelerator. Four atoms of darmstadtium were produced in the first experiment.
Darmstadtium is a chemical element with the symbol Ds and atomic number 110.
It is an extremely radioactive synthetic element.
Darmstadtium based on its position in the periodic table, proposes three different reasonable valence electron configurations for this element is 2.
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[tex]S_8 +120_2[/tex] → [tex]8SO_3[/tex] has been balanced correctly.
What is a balanced chemical equation?A balanced equation is an equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge is the same for both the reactants and the products.
[tex]S_8 +120_2[/tex] → [tex]8SO_3[/tex] has been balanced correctly and the rest are not balanced.
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How many moles of MgBr2 are 75.24g of MgBr2
Answer:
0.409 mol
Explanation:
The formula to find he number of moles is:
No. of moles = [tex]\frac{mass}{Mr}[/tex]
Mr of MgBr₂ = 24.3 + (79.9 × 2) = 184.1
Mass = 75.25g
So, no. of moles = [tex]\frac{75.24}{184.1}[/tex]
No. of moles = 0.409 mol [to 3 significant figures]
Part A
Measure and record the masses of all the metal strips you set out in front of the test tubes.
B IU x X2 10pt
iii
Imi
hili
ole
Test tube
Metal
Mass (g)
1
magnesium
2.
zinc
3
copper
magnesium
4
5
zinc
6
copper
This is a good answer:
Select the correct answer from each drop-down menu. A balloon holds a certain volume of air. In what three ways can the volume of the balloon be increased? the number of air molecules in the balloon the temperature of the balloon the pressure on the balloon
On increasing temperature , On decreasing pressure , on increasing the number of air molecules in the balloon volume will increase
What is Ideal Gas Law ?The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases.
An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).
Considering the gas inside the balloon to be ideal
We can understand from the ideal gas equation that
V∝ Temperature
V∝ Number of air molecules
V ∝ (1/P)
Therefore on increasing temperature volume will increase ,
On decreasing pressure volume will increase
and on increasing the number of air molecules in the balloon volume will increase.
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