Answer:
When excited electrons fall back to the ground state, they release energy in the form of photons of light. These photons of light create the colors observed in a line-emission spectrum.
Explanation:
HELP a #QUEEN out pls??
Type the correct answer in each box.
Balance the equation.
_____SiO2 + ______CaC2 → _____Si + _______CaO + _____CO2
The coefficients, in order of the blanks, are 5, 2, 5, 2, 4.
a ceiling fan's blades collect dust faster than other objects in a room. the constant pushing and rubbing against the air provide a cool breeze for the people in the room. what causes the ceiling fan´s blade to collect dust so quickly.
As the blades rotate, they experience frictional forces as they `rub' against the air; this knocks electrons around, causing the blades to build up a net charge. The charged dust particles then stick to the charged areas of the blades. "The leading edge of the blades usually develops the thickest layer of dust.
To solve this we must be knowing each and every concept related to dust. Therefore, frictional forces allow the ceiling fan´s blade to collect dust so quickly.
What is dust?Dust stirred up by automobiles on the road may account for 33% overall air pollution. Deposits of vehicle or commercial exhaust gas, particles through tire and braking wear, dust from paved streets or potholes, plus dust from building sites all contribute to road dust.
As the blades revolve, frictional forces cause them to 'rub' against the air, knocking electrons around and allowing the blades to accumulate a net charge. The electrified dust particles are subsequently attracted to the charged portions of the blades. Typically, the sharp end of the blades creates the heaviest coating of dust.
Therefore, frictional forces allow the ceiling fan´s blade to collect dust so quickly.
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How many milliliters of 4.00 M NaOH are required to exactly neutralize 50.0 milliliters of a 2.00 M solution of HNO3 ?
Answer: The volume of [tex]NaOH[/tex] required is 25.0 ml
Explanation:
According to the neutralization law,
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1[/tex] = basicity [tex]HNO_3[/tex] = 1
[tex]M_1[/tex] = molarity of [tex]HNO_3[/tex] solution = 2.00 M
[tex]V_1[/tex] = volume of [tex]HNO_3[/tex] solution = 50.0 ml
[tex]n_2[/tex] = acidity of [tex]NaOH[/tex] = 1
[tex]M_1[/tex] = molarity of [tex]NaOH[/tex] solution = 4.00 M
[tex]V_1[/tex] = volume of [tex]NaOH[/tex] solution = ?
Putting in the values we get:
[tex]1\times 2.00\times 50.0=1\times 4.00\times V_2[/tex]
[tex]V_2=25.0ml[/tex]
Therefore, volume of [tex]NaOH[/tex] required is 25.0 ml
The volume of 4.00 M NaOH is required to exactly neutralize 50.0 ml of a solution of a 2.00 M solution of [tex]HNO_3[/tex] is 25.0 ml.
What is [tex]HNO_3[/tex]?[tex]HNO_3[/tex] is nitric acid also known as the spirit of niter. It is colorless in its original form but appears yellow-colored.
By the neutralization law
[tex]n_1M_1V_1 = n_2M_2V_2[/tex]
n1 = 1
M1 = 2.00
M2 = 4.00
V1 = 50.0 ml
n2 = NaOH = 1
Putting the value in the formula
[tex]1 \times 2.00 \times 5.00 ml = 1 \times 4.00 \times V_2\\\\V_2 = 25.0\; ml[/tex]
Thus, the volume of NaOH required is 25.0 ml.
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If 34.2 g of NaOH are dissolved in water to make a 750 mL solution, what is the molarity of the solution?
Answer:
1.14 M
Explanation:
First divide the mass of NaOH by the molar mass of NaOH. Then divide by the volume to get molarity.
34.2 g / 39.997 g/mol = 0.855 mol NaOH
0.855 mol NaOH / 0.750 L = 1.14 M NaOH
Which pair of elements is in the same period? (Check ALL that apply) *
17 points
G
F
D
R
J
Answer:
D and R are in the same period
Explanation:
remember groups are vertical and periods are horizontal!
A student prepares four different aqueous NaCl solutions according to the table. Which solution will have the highest molarity?
Answer:
what did you end up guessing
Explanation:
Select the correct answer.
Which statement best describes how chemical equations demonstrate conservation of mass?
A.
The number of reactants is the same as the number of products.
B.
The compounds are the same on each side of the reaction.
C.
The number of atoms of each element is the same on each side of the equation.
D.
The state of matter is the same on each side of the equation.
"C" is correct.
The Law of Conservation of Mass states that matter can be neither created nor destroyed. This is evident in chemical equations as you will always start and end with the same amount of atoms of every element. They are all still there; they have just been rearranged.
Answer: C) The number of atoms of each element is the same on each side of the equation.
Explanation: Mass cannot be created nor destroyed.
What is the job or function of cell walls in plant cellls
Answer:
The cell wall surrounds the plasma membrane of plant cells and provides tensile strength and protection against mechanical and osmotic stress. It also allows cells to develop turgor pressure, which is the pressure of the cell contents against the cell wall.
Explanation:
ion
A chemical equation representing the reaction of water (HOH) and hydrochloride acid (HCI) is shown.
HOH + HCl + Cl + H2O
Which of the following statements best explains the chemical action of the reactants in the equation?
Answer:
That is Hydrolysis reaction.
[tex]HCl _{(aq)} \: + \: _{(aq)} \: - - > \: H ^{ + }_{(aq)} \: + \: Cl {}^{ - } _{(aq)}[/tex]
65 g of NaOH is dissolved to make 500 mL of solution. Find moles of NaPH and Molarity of solution.
Answer:
3.25 M
Explanation:
Number of moles = mass/ molar mass
mass of NaOH = 65 g
Molar mass of NaOH = 40 g/mol
Number of moles of NaOH = 65g/40 g/mol = 1.625 moles
Let us recall that;
n = CV
n = number of moles of solute
C = concentration of solution
V = volume of solution
C = n/V
n = 1.625 moles
V = 500/1000 L = 0.5 L
C = 1.625 moles/0.5
C = 3.25 M
Someone help me out with this brain pop ⚠️
pls show your work will mark brainliest
Answer:
0.047 moles
Explanation:
From the question,
Applying
PV = nRT............. Equation 1
Where P = Pressure of CH₄ gas, V = Volume of CH₄ gas, n = number of moles of CH₄ gas, R = Molar gas constant.
make n the subject of the equation
n = PV/RT............. Equation 2
Given: P = 660 torr = (660×0.00131579) atm = 0.868 atm, V = 1300 mL = (1300/1000) L = 1.3 L, T = 20 °C = (20+273) K = 293 K
Constant: R = 0.082 atm.dm³/K.mol
Substitute these values into equation 2
n = (0.868×1.3)/(0.082×293)
n = 1.1284/24.026
n = 0.047 mole
HI dissociates to form 12 and Hz: 2HI(g) → H2(g) + 12(9) If the concentration of Hl changes at a
rate of -0.45 mol L's? what is the rate of appearance of 12(g)?
Based on the rate of disappearance of HI, the rate of appearance of I₂ is 0.225 mol/L/s.
What is rate of reaction?
The rate of a reaction is the rate at which reactant molecules are converted to product or the rate at which product molecules are formed.
Rate of reaction = change in concentration of reactant or product/timeFrom the equation of the reaction, 2 moles of HI produces 1 mole of I₂.
The rate of disappearance of HI is -0.45 mol/L/s
The rate of appearance of I₂ will be 0.45/2 mol/L/s = 0.225 mol/L/s.
Therefore, the rate of appearance of I₂ is 0.225 mol/L/s.
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10 How does no-till farming help the environment?
A It decreases soil erosion.
C It increases fertilizer use.
B It increases soil removal.
D It decreases crop yield.
Answer: Answer is A it will decrease soil erosion
Explanation:it just will trust me
Answer:
A.
Explanation:
the soil will not loosen when u till it
Describe how the freeze-thaw cycle of ice will change the shape of this rock over time. PLSSSS HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!✋
Freeze-Thaw Weathering
This action can widen the cracks in the rock, and when the temperature rises above freezing, the ice thaws, allowing the water to seep further into the cracks. As this process of freezing and thawing happens repeatedly, the rock begins to weaken and eventually breaks apart into angular fragments.
Answer:
Physical weathering is caused by the effects of changing temperature on rocks, causing the rock to break apart. The process is sometimes assisted by water. ... Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
Explanation:
hope this helps
Which best describes the relationship between the terms frequency, wavelength, and hertz?
Answer:
The correct answer is - Frequency is the number of wavelengths, which is measured in hertz.
Explanation:
Frequency is the number of waves that go through a fixed point at a particular time. Hertz is the SI unit for frequency which means that one hertz is equal to a unit number of waver passes in a unit time to a fixed point.
As the frequency of a wave increases which means the number of waves increases in the unit time, the shorter the wavelength will be.
a higher frequency wave has more energy than a lower frequency wave with the same amplitude.
Pt4 science......
Select correct answer ♡ !
What are the mole ratios of the following chemical equation: C3H8 + 5O2 --> 3CO2 + 4H2O?
Answer:Redox and combustion.
Explanation:
C3H8) reacts with oxygen in the air, so C3H8(g) + 5O2(g) = 3CO2(g) + 4H2O(g) Classification: Redox and combustion.
Sodium chlorate is used to produce yellow fireworks. Heating sodium chlorate creates oxygen and sodium chloride. How many moles of sodium chlorate is needed to produce 5.70 moles of oxygen?
https://www.geneva304.org/Downloads/ch%209%20key6.pd
this is what i found add an "f" at the end and search
A ballon is filled with 1.22 L of gas at 286 K is heated until the volume is 2.86 L while the pressure remains constant. What is the temperature of the gas in kelvin?
Answer:
670.45 K
Explanation:
Given that,
Initial volume, V₁ = 1.22 L
Initial temperature, T₁ = 286 K
Final volume, V₂ = 2.86 L
We need to find the new temperature of the gas. The relation between the volume and the temperature is given by :
[tex]\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}\\\\T_2=\dfrac{V_2T_1}{V_1}\\\\T_2=\dfrac{2.86\times 286}{1.22}\\\\T_2=670.45\ K[/tex]
So, the new temperature of the gas is equal to 670.45 K.
describe what happens when atoms release light?
Answer:
hi
Explanation:
Light is the result of electrons moving between defined energy levels in an atom, called shells.
What number represents a mole?
5
1
4
14
8
6
19
1. The production of a slightly soluble solid compound in a double-
displacement reaction results in the formation of a
a. gas.
b. precipitate.
C. combustion reaction.
d. halogen.
Answer: precipitate
Explanation:
Can you identify what object is being represented by the model on the right?
basketball
cell
Earth
The answer is. B. Cell
Answer:
Cell lol
Explanation:
answer B
Compare a low-dose rate internal radiation treatment to a high dose rate internal treatment. What do you think are the positives and negatives of each?
Explain what helps convert non-rich oxygen blood cells back to oxygen rich cells?
Answer:
As blood travels through the body, oxygen is used up, and the blood becomes oxygen poor. Oxygen-poor blood returns from the body to the heart through the superior vena cava (SVC) and inferior vena cava (IVC), the two main veins that bring blood back to the heart.
Explanation:
If Lead (II) nitrate reacted with iron (III) acetate what would the balanced formula be?
Answer:
Explanation:
3Pb(ii)(NO3)2 + 2Fe(iii) ( C2H3O2 )3 ===> 3Pb( C2H3O2)2 + 2Fe(NO3)3
I know you have likely been given this as a homework assignment, but in real life I doubt you would be able to see any reaction taking place. The products are likely both soluble and both ionize, so I don't think you will get any kind of reaction taking place.
The equation however is balanced.
If the hydroxide ion concentration of a solution is 3.26 x 10-6 M, is it an acidic or a basic solution?
Answer: It is a basic solution with pH =8.51
Explanation:
We were given that hydroxide ion concentration [OH-] as 3.26 x 10-6 M
But We know thar
[OH-] [H+] = 1 × 10^-14
To get the Hydrogen ion [H+] concentration, we have that
[H+] = 1 × 10^-14 M/[OH-]
= 1 × 10^-14 M/3.26 x 10-6 M
= 3.067 x 10^-9 M
But, pH = - log [H+]
Therefore,
pH = - log (3.067 x 10^-9)
pH=8.51
when pH > 7, The solution is basic, therefore a solution with pH =8.51 is basic.
3. Move the slider on the burette to the top to add about 25 mL of NaOH to the flask. What
happens, and what does this tell you about the pH of the flask?
Page Break
LED
Answer:
When you move the burette slider to the top of a flask and add about 25 mL of NaOH to the flask, you will cause a concentration of OH- molecules. This will make the solution become a basic solution and make the litmus paper blue.
Explanation:
After reading your question, we can see that you are carrying out a test to discover the nature of the pH of a solution. This type of test uses litmus paper, which is an indicator of the presence of acids and bases, being able to determine the pH of a solution. This paper is soaked in organic ink and when placed in an acidic solution, it is red in color. However, when placed in a basic solution it has a blue color.
An acidic solution is one that has a high concentration of H+ atoms and has the ability to donate electrons. The basic solution, on the other hand, has a high concentration of OH- and has the capacity to receive electrons.
When you move the burette slider to the top of a flask and add about 25 mL of NaOH to the flask, you will cause a concentration of OH- molecules. This will make the solution become a basic solution and make the litmus paper blue, that is, the solution has the basic pH.
Write two paragraphs about what would happen if your whole body was put in a low pressure environment ?
Answer:
Reduced air pressure also has a serious effect on the human body. Reduced air pressure means that there is less oxygen available to the body. For lungs to inflate, the air pressure in your lungs has to be less than the air outside the lungs. This is because air moves from high-pressure areas to low-pressure areas.
Explanation:
Reduced air pressure also has a serious effect on the human body. Reduced air pressure means that there is less oxygen available to the body. For lungs to inflate, the air pressure in your lungs has to be less than the air outside the lungs. This is because air moves from high-pressure areas to low-pressure areas.