Answer:
The benefits of Fluoride are rebuild (remineralize) weakened tooth enamel.slow down the loss of minerals from tooth enamel.reverse early signs of tooth decay.prevent the growth of harmful oral bacteria
Answer:
Fluoride is often called nature's cavity fighter and for good reason. Fluoride, a naturally-occurring mineral, helps prevent cavities in children and adults by making the outer surface of your teeth (enamel) more resistant to the acid attacks that cause tooth decay.
Estimate your de Broglie wavelength when you are running. (For this problem use h = 10^−34 in SI units and 1 lb is equivalent to 0.45 kg.) For the computation, estimate how fast you can run in meters per second.
A. your running speed ______ m/s
B. your mass ______kg
C. your de Broglie wavelength ______ m
Answer:
A. your running speed 1.5 m/s
B. your mass 70 kg
C. your de Broglie wavelength [tex]6.32x10^{-36}[/tex]m
Explanation:
Hello there!
In this case, since the equation for the calculation of the Broglie wavelength is:
[tex]\lambda =\frac{h}{m*v}[/tex]
We can assume a running speed of about 1.5 m/s and a mass of 70 kg, so the resulting Broglie wavelength is:
[tex]\lambda =\frac{6.626x10^{-34}kg\frac{m}{s} }{70kg*1.5\frac{m}{s} }\\\\\lambda =6.32x10^-36m[/tex]
Best regards!
2 Nal + Pb(NO3)2
2 NaNO3
+
Pb12
What are the reactants in this equation?
Answer:
[tex]\boxed {\boxed {\sf A. \ NaI \ and \ Pb(NO_3)_2}}[/tex]
Explanation:
In a chemical reaction, the reactants are the substances that start the reaction and change into other substances. The results at the end of the reaction are products.
Typically, the reactants are to the left of the arrow, while products are to the right.
reactants ⇒ productsWe are given this chemical equation:
[tex]2 \ NaI + Pb(NO_3)_2 \rightarrow 2NaNO_3 +PbI_2[/tex]
We are asked to find the reactants. Remember, these go into the reaction and are on the left.
[tex]\bold {2 \ NaI + Pb(NO_3)_2 } \rightarrow 2NaNO_3 +PbI_2[/tex]
Therefore, the reactants are NaI (sodium iodide) and Pb(NO₃)₂ (lead nitrate). Choice A is correct.
When would a topographic map be useful?
Answer:
Topographic maps are used by hikers and backpackers to plan routes, estimate travel times, find water, good campsites, and track their progress on hikes. They're designed to depict the three dimensional shape of the world (mountains, valleys, plains, etc.)
Explanation:
A 90-m3 basement in a residence is found to be contaminated with radon coming from the ground through the floor drains. The concentration of radon in the room is 1.5 Bq/L under steady-state conditions. The room behaves as a CSTR and the decay of radon is a first-order reaction with a decay rate constant of 2.09 3 1026 s21 . If the source of radon is closed off and the room is vented with radon-free air at a rate of 0.14 m3 /s, how long will it take to lower the radon concentration to an acceptable level of 0.15 Bq/L
Answer:
25 minutes
Explanation:
V = Volume = [tex]90\ \text{m}^3[/tex]
[tex]C_0[/tex] = Radon concentration under steady state = 1.5 Bq/L
k = Radon decay rate = [tex]2.09\times 10^{-6}\ \text{s}^{-1}[/tex]
[tex]Q[/tex] = Venting rate = [tex]0.14\ \text{m}^3/\text{s}[/tex]
[tex]C_f[/tex] = Final concentration of radon = 0.15 Bq/L
Theoretical detention time is given by
[tex]\theta=\dfrac{V}{Q}\\\Rightarrow \theta=\dfrac{90}{0.14}\\\Rightarrow \theta=642.86\ \text{s}[/tex]
We have the relation
[tex]C_f=C_0e^{-(\dfrac{1}{\theta}+k)t}\\\Rightarrow t=\dfrac{\ln\dfrac{C_f}{C_0}}{-(\dfrac{1}{\theta}+k)}\\\Rightarrow t=\dfrac{\ln\dfrac{0.15}{1.5}}{-(\dfrac{1}{642.86}+2.09\times 10^{-6})}\\\Rightarrow t=1478.25\ \text{s}=\dfrac{1478.25}{60}=24.63\approx 25\text{minutes}[/tex]
The time taken to reach the acceptable level of concentration is 25 minutes.
HELP ASAP PLEASE!!! :)
Answer:
Alkane
Explanation:
Alkenes have CH in their condensed formulas and alkynes have C in their condensed formulas. There are only CH3 and CH2 so it's an alkane.
1. What do you call the continuous change in position of a body relative to a pon
reference point, as measured by a particular observer in a particular frame
of reference?
Answer:
In physics, motion means a continuous change in the position of a body relative to a reference point, as measured by a particular observer in a particular frame of reference.
Explanation:
Crosses between true-breeding plants with white flowers produced plants with only _____ flowers white or purple
Which of the following is NOT an abiotic factor that influences an ecosystem?
Amount of water available
Average rainfall
Average temperature
Number of different animals
Answer:
Number of different animals
Explanation:
Number of different animals is not an abiotic factor that influences an ecosystem rather it is a biotic factor.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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The particle in the atom with a negative charge is the...
Answer: electrons
Explanation: An atom consists of a positively charged nucleus, surrounded by one or more negatively charged particles called electrons.
when 70.0 grams of mno2 reacted with 128.0 grams of hcl, the reaction resulted in a 62.7% yield of chlorine gas. what is the actual yield of chlorine gas in grams? Mno2 + HCI —> MnCl2 + h2o + cl2
Answer:
35.8g of Cl₂ is the yield
Explanation:
Based on the reaction:
MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂
1 mole of MnO₂ and 4 moles of HCl react producing 1 mole of Cl₂
To solve this question we must find limiting reactant. with limiting reactant we can find the theoretical yield of Cl₂. As the actual yield is the 62.7% we can find actual yield of Cl₂ in grams:
Moles MnO₂ -Molar mass: 86.9368g/mol-:
70.0g * (1mol / 86.9368g) = 0.805 moles
Moles HCl -Molar mass: 36.46g/mol-:
128.0g * (1mol / 36.46g) = 3.51 moles
For a complete reaction of 3.51 moles of HCl are required:
3.51 moles HCl * (1mol MnO₂ / 4mol HCl) = 0.878 moles MnO₂.
As there are just 0.805 moles of MnO₂, MnO₂ is limiting reactant.
1 mole of MnO₂ produce 1 mole of Cl₂. The theoretical moles of Cl₂ produced are 0.805 moles.
As the yield is of 62.7%, the yield of Cl₂ is:
0.805 moles * (62.7 / 100) = 0.505 moles Cl₂. In grams:
0.505 moles Cl₂ * (70.906g / mol) =
35.8g of Cl₂ is the yield4
The work done when a gas is compressed in a cylinder is 338 J. At the same time,
it absorbs 142 J of heat from the surroundings. Compute the change in energy of
the system.
Answer:
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
Explanation:
kh uh
arrange
these liquids in order of increasing surface tension: water,
hexane, ethanol.
The magnitude of surface tension of liquid depends on the attractive forces between the molecules. Arrange the following in increasing order of surface tension:
water, alcohol (C2H5OH) and hexane [CH3(CH2)4CH3)].
Answer:
Hexane, Methanol, Water
Explanation:
I did the assessment
NEED HELP FOR THIS ONE
Answer:
C₆H₁₂O₆ + 6 O₂ = 6 CO₂ + 6 H₂O
2 KO₂ + H₂O = 2 KOH + 1.5 O₂
Explanation:
Let's consider the following unbalanced equation.
C₆H₁₂O₆ + O₂ = CO₂ + H₂O
We will start balancing H atoms (higher atomicity) by multiplying H₂O by 6.
C₆H₁₂O₆ + O₂ = CO₂ + 6 H₂O
Then, we will balance C atoms by multiplying CO₂ by 6.
C₆H₁₂O₆ + O₂ = 6 CO₂ + 6 H₂O
Finally, to get the balanced equation, we will multiply O₂ by 6.
C₆H₁₂O₆ + 6 O₂ = 6 CO₂ + 6 H₂O
---
Let's consider the following unbalanced equation.
KO₂ + H₂O = KOH + O₂
We will multiply KO₂ and KOH by 2 to balance K and H atoms.
2 KO₂ + H₂O = 2 KOH + O₂
Finally, to get the balanced equation, we will multiply O₂ by 1.5.
2 KO₂ + H₂O = 2 KOH + 1.5 O₂
Which of these benefits the grassland by allowing light, warmth, moisture, and nutrients back into the soil?
fires
ponds
trees
rainfall
Answer:
Trees
Explanation:
I think sorry if I get it wrong
A flask contains a 1.00 mole of neon gas and 2.00 moles of argon gas. If the total pressure of the gases is 150.0 kPa, then what is the partial pressure of the argon gas in kPa?
Answer:
Partial pressure of Ar = 100.5 KPa
Explanation:
The following data were obtained from the question:
Number of mole of Ne = 1 mole
Number of mole of Ar = 2 moles
Total pressure = 150.0 KPa
Partial pressure of Ar =?
Next, we shall determine the mole fraction of Argon (Ar). This can be obtained as follow:
Number of mole of Ne = 1 mole
Number of mole of Ar = 2 moles
Total mole = 1 + 2 = 3 moles
Mole fraction of Ar = mole of Ar / total mole
Mole fraction of Ar = 2/3
Mole fraction of Ar = 0.67 mole
Finally, we shall determine the partial pressure of argon (Ar). This can be obtained as follow:
Mole fraction of Ar = 0.67 mole
Total pressure = 150.0 KPa
Partial pressure of Ar =?
Partial pressure = mole fraction of gas × total pressure
Partial pressure of Ar = 0.67 × 150
Partial pressure of Ar = 100.5 KPa
which sentences in the passage are true?
Answer:
First and last sentence .♀️
Explanation:
An important thing to keep in mind about the Reading Comprehension section of the GRE as we use PowerPrep online to study is that it is just that—reading comprehension. In other words, as difficult as it may seem, and it can be pretty tricky, the test makers will always give us all the information we need in the passage to answer the question.
Which oficial the following organisms si not an autotroph
A. mushroom
B. grass
C. tree
D. moss
Answer:
A. mushroom
Explanation:
3. What is the mass % of a solution that contains 36g KCl in 475g of water?
Answer:
%KCl = 7.05%
%Water = 92.95%
Explanation:
Step 1: Given data
Mass of KCl (solute): 36 gMass of water (solvent): 475 gStep 2: Calculate the mass of the solution
The mass of the solution is equal to the sum of the masses of the solute and the solvent.
m = 36 g + 475 g = 511 g
Step 3: Calculate the mass percentage of the solution
We will use the following expression.
%Component = mComponent/mSolution × 100%
%KCl = 36 g/511 g × 100% = 7.05%
%Water = 475 g/511 g × 100% = 92.95%
How do you balance this:
Br2 + H2O + SO2 = HBr + H2SO4
Answer:
Br2+ 2H2O + SO2= 2HBr + H2SO4
Let's Compare the left side of the equation to the right side of the equation.
Left: Br= 2, H= 2, S= 1, O = 1+2
Right: Br=1, H= 1+2, S=1, O= 4
We can see that only S is balanced and not the other 3 elements.
I'll try to make each element balance.
For Br; I'll multiply by 2 on the left to make it equal to the right.
For H; Since the 2 for Br on the right affected also H, that H ( for HBr) Already has a 2, but then it adds with the other H2( for H2SO4) to give a total of 4 H on the right side. But then there's only 2 H on the left. so we multiply that 2 by a 2 ( which is written infront of the H2O to give a total of 4 H on the left side.
For O; Because of the 2 infront of the H2O, it affects the O in H2O..so now we have 2 O plus the 2 O ( in SO2) to give a total of 4 O which is equal to the right side.
The overall redox equation for the voltaic cell can be written as ^^^. What is being reduced in this forward reaction?
Answer:
Cu⁺² is being reduced in that reaction.
Explanation:
Zn(s) + Cu⁺²(aq) → Zn⁺²(aq) + Cu(s)When a substance is reduced, its oxidation number is reduced -changing to a lower value than original-.
Cu⁺² turned into Cu. Meaning that the oxidation number changed from +2 to 0.
Thus, Cu⁺² is being reduced in that reaction.
9.16 liters of CO2 weighs how many grams?
Your answer
Answer:
18.0g of CO₂ are present in 9.16L
Explanation:
To solve this question we must use:
PV = nRT
In order to find the moles of the gas and with its molar mass (44.01g/mol for CO₂) we can find the mass of the gas
Assuming STP conditions:
P = 1atm at STP
V = 9.16L
n are the moles of CO₂
R = 0.082atmL/molK
T = 273.15K
Replacing:
PV / RT = n
1atm*9.16L / 0.082atmL/molK*273.15K = n
0.409 moles = Moles of CO₂
The mass is:
0.409 moles CO₂ * (44.01g / mol) =
18.0g of CO₂ are present in 9.16LWhat is the mass of a rectangular piece of copper 24.4cm x 11.4 cm x 7.9 cm? The density of copper is 8.92g/cm3.
The mass of the rectangular piece of copper is 18,869 g (approx).In conclusion, the mass of a rectangular piece of copper with dimensions 24.4cm x 11.4 cm x 7.9 cm and a density of 8.92 g/cm³ is 18,869 g (approx.).
The given dimensions of the rectangular piece of copper are:Length = 24.4 cmWidth = 11.4 cmHeight = 7.9 cmThe formula to calculate the mass of an object is given by;
Mass = Density x Volume
Here, the density of copper is given as 8.92 g/cm³.
Therefore, the first step is to calculate the volume of the rectangular piece of copper.The formula to calculate the volume of a rectangular object is given by:
Volume = Length x Width x Height
So,Volume = 24.4 cm x 11.4 cm x 7.9 cm= 2115.432 cm³Now we will use the mass formula:
Mass = Density x Volume= 8.92 g/cm³ x 2115.432 cm³= 18,869.27824 g= 18,869 g (approx.)
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Predict the product for the following reaction sequence.3,4-dimethyl-7-nonanol 3,4-dimethyl-7-nonanone 6,7-dimethyl-3-nonanone 6,7-dimethyl-3-nonanal 6,7-dimethyl-3-nonanol
Answer:
Hello your question is incomplete attached below is the complete question
answer : 6,7-dimethyl-3-nonanone ( B )
Explanation:
The product for the following reaction sequence as attached below is
6,7-dimethyl-3-nonanone
The following reaction sequence can be categorized under Carbon Nucleophiles.
Carbon Nucleophiles which can be used to convert aldehydes and ketones into carboxylic acids or alkenes.
The product for the given reaction sequence is 6,7-dimethyl-3-nonanone.
IUPAC (International Union of Pure and Applied Chemistry) naming is a systematic method used to name chemical compounds according to a set of rules established by the IUPAC.
The purpose of IUPAC naming is to provide a consistent and unambiguous way to communicate the structure of a compound through its name.
The outcome of the subsequent chain of reactions, which is appended below, is 6,7-dimethyl-3-nonanone
Under the heading of Carbon Nucleophiles, the following reaction chain can be categorised.
Aldehydes and ketones can be transformed into carboxylic acids or alkenes using carbon nucleophiles.
Thus, the answer is 6,7-dimethyl-3-nonanone.
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Your question seems incomplete, the probable complete question is:
Can someone help me with this 3 questions I’ll mark brainliest spam answers will be reported
Answer:
1. stomach
2. veins
3.both are functions
Explanation:
1. The cardiovascular system consists of the heart, and a closed system of vessels called arteries, veins, and capillaries. (Stomach is not included)
2.The inferior vena cava is the largest vein in the body and carries deoxygenated blood from the lower half of the body into the heart
3. Blood transports oxygen and nutrients to the lungs and tissues, and brings waste products to the kidneys and liver, which filter and clean the blood.
Hope this helps!
Calculate the pH when [H]= 7.5 x 10^-12M
Answer:
11.1249387366083
Explanation:
you do -log([H+]
What is orbit? A. An increase in centripetal motion and mass friction. B. Resistance of an object to avoid friction. C. Gravity causing a curved path as an object tries to go straight. D. How well an object floats.
Answer:
C. gravity causing a curved path as an object tries to go straight.
The formula for chromium (vi)bromate
Answer: The formula of chromium fluoride is CFr2.
most sedimentary rock forms in the ocean.This is because oceans-
Answer:
Explanation:
are where most bits of broken rock are deposited.
This is because oceans are where most bits of broken rock are deposited.
The reason for using 1-propanol as the solvent of choice for recrystallization is that triphenylphosphine oxide is more soluble in 1-propanol than the alkene product because triphenylphosphine oxide can use its oxygen to hydrogen-bond to 1-propanol, whereas the alkene has no hydrogen-bonding capability. Triphenylphosphine oxide, therefore, is removed based on its polarity and H-bonding ability.
a. True
b. False
Answer:
True
Explanation:
Hydrogen bonding is a bond that exists between hydrogen and a highly electronegative element such as oxygen, nitrogen, fluorine etc.
The greater solubility of the triphenylphosphine oxide owes to the hydrogen bonded interaction between it and the 1-propanol.
The alkene lacks such hydrogen bonded interaction because it does not have a highly electronegative atom in its structure.
Hence, triphenylphosphine oxide is removed based on its polarity and hydrogen bonding ability.
What is orbit? A. An increase in centripetal motion and mass friction. B. Resistance of an object to avoid friction. C. Gravity causing a curved path as an object tries to go straight. D. How well an object floats.
Answer:
c
Explanation: