What are cilia?

smooth covering
hair like structures
a tail
all of the above

Answer:

check below

Explanation:

c) Concentrated sulphuric acid is used a drying agent.

d) (use any one of them) Concentrated phosphoric acid, hot aluminium oxide, calcium chloride , anhydrous calcium sulphate

Answer:

12c) it is used as a drying agent

d) anhydrous calcium chloride

calcium oxide can also be used as a drying agent

Answer:

option D

Explanation:

first quantum number of a 2s2

n = 2

second quantum number of a 2s2

l = 0 to n-1

l = 0, 1

For s orbital

l = 0

third quantum number of a 2s2

ml = - l to +l

ml = 0

fourth quantum number of a 2s2 electron be

?½ = spin down

½ = spin up

2s2 has 2 electrons 1 spin down and 1 spin up (starts with spin down)

ms = +1/2

Answer:

+1/2

Explanation:

Answer:

substitutions, deletions and insertions

Answer: I think it is ‘Genetically diverse’

Explanation:

Answer:

A

Explanation:

the chloroplast holds the water , nutrients

Answer:

[tex]\boxed {\boxed {\sf D. \ Vacuoles}}[/tex]

Explanation:

First, let's examine each answer choice.

A. Chloroplasts

B. Lysosomes

C. Mitochondria

D. Vacuoles

Since the question asks us to pick the sac-like structures that store materials in cells, choice D: vacuoles is correct.

Answer:

[tex]\boxed {\boxed {\sf B. \ -8.9 \ m/s^2}}[/tex]

Explanation:

Acceleration is found by dividing the change in velocity by the change in time.

[tex]a=\frac {v_f-v_i}{t}[/tex]

The parachute slows from 85 m/s to 45 m/s. Therefore, the final velocity is 45 meters per second and the initial velocity is 85 meters per second. The time is 4.5 seconds.

[tex]v_f= 45 \ m/s \\v_i= 85 \ m/s \\t= 4.5 \ s[/tex]

Substitute the values into the formula.

[tex]a= \frac {45 \ m/s- 85 \ m/s}{4.5 \ s}[/tex]

Solve the numerator and subtract.

[tex]a= \frac {-40 \ m/s}{4.5 \ s}[/tex]

Divide.

[tex]a=-8.888888889 \ m/s/s[/tex]

If we round this to the nearest tenth, the 8 in the hundredth place tells us to round the 8 up to a 9.

[tex]a \approx -8.9 \ m/s/s= -8.9 \ m/s^2[/tex]

The acceleration of the parachute is approximately -8.9 meters per square second. The value is negative because the parachute is slowing down.

Answer:

With the policies of containment, the United States hoped to effectively stop the spread of communism and their newest threat. After the war, the United States and the Soviet Union had very different ideas on how to rebuild.

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:

Answer:

Explanation:

The reaction is violent but safe, provided the procedure is followed exactly. ... Chemicals. Magnesium powder (HIGHLY FLAMMABLE), 0.25 g (note 4); Copper(II) oxide powder ... top must NOT be hot when the magnesium powder/copper oxide mix is added. ... After one or two minutes (be patient) a vigorous reaction occurs.

Answer:  16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

The balanced chemical equation is:

[tex]3H_2+N_2\rightarrow 2NH_3[/tex]

According to stoichiometry :

[tex]3\times 22.4=67.2L[/tex] of [tex]H_2[/tex]  produce = [tex]2\times 22.4=44.8L[/tex] of [tex]NH_3[/tex] at STP

Thus 24.5 L of [tex]H_2[/tex]  will produce= [tex]\frac{44.8}{67.2}\times 24.5=16.3L[/tex] of [tex]NH_3[/tex] at STP

Thus 16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP

Answer:

0.25 M

Explanation:

Answer:

option B,C and A are compound

Answer:

Caustic Base

Explanation:

"Barium hydroxide forms a strong caustic base in aqueous solution. It has many uses, e.g., as a test for sulphides; in pesticides; in the manufacture of alkali and glass. Use of barium hydroxide lime rather than soda lime, high sevoflurane concentration, high absorbent temperature, and fresh absorbent use."

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Hope I Helped, Feel free to ask any questions to clarify :)

Have a great day!

More Love, More Peace, Less Hate.

    -Aadi x

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

Answer:

2.9x10⁻⁷L is the volume this amount of gas occupy

Explanation:

Assuming there are 7.8x10¹⁵ atoms

Based on the general gas law:

PV = nRT

Where P is pressure = 1atm

V is volume = Our incognite

n are moles of the gas:

7.8x10¹⁵ atoms * (1mol / 6.022x10²³ atoms) = 1.30x10⁻⁸ moles of gas

R is gas constant = 0.082atmL/molK

And T is absolute temperature = 273.15K at STP

Solving for Volume:

V = nRT/P

V = 1.30x10⁻⁸ moles*0.082atmL/molK*273.15K / 1atm

V = 2.9x10⁻⁷L is the volume this amount of gas occupy

Answer:

[tex]m_{CO_2}=0.88g[/tex]

Explanation:

Hello there!

In this case, since we are talking about a decomposition reaction whereby calcium carbonate is decomposed to calcium oxide and carbon dioxide according to the following chemical equation:

[tex]CaCO_3\rightarrow CaO+CO_2[/tex]

Next, we must recall the law of conservation of mass which states that matter cannot be neither created nor destroyed so the mass of calcium carbonate equal the addition of the mass of both calcium oxide and carbon dioxide:

[tex]m_{CaCO_3}=m_{CaO}+m_{CO_2}[/tex]

Which must be solved for the mass of carbon dioxide as we are given those of calcium carbonate and calcium oxide:

[tex]m_{CO_2}=m_{CaCO_3}-m_{CaO}\\\\m_{CO_2}=2.00g-1.12g\\\\m_{CO_2}=0.88g[/tex]

Best regards!

Answer:

A

Explanation:

because the charge of Li ion is +1 well I don't know the explanation yet but I'm sure about the answer

Answer:

anion

Explanation:

anion undergoes reduction.

cation undergoes oxidation.

The ions are categorized according to the process of oxidation and reduction. The ion usually undergoes reduction is an anion.

A process involving the partial or complete gain of electrons and loss of oxygen. The ions acquire a net negative charge on them.

Thus, anions usually undergo a reduction.

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Answer:

4

Explanation:

1N2 + 3H2  2NH3

Answer:

b and c

Explanation:

sorry if i'm wrong

Answer:

b, c, d, e

Explanation:

CaseAnswer:

-Mole of stearic acid used = 1.3*10^-3 mol

-Molecules of stearic acid there would be in 1 mole of stearic acid = 7.994*10^20 molecules

Explanation:

Know information from the problem are:

Mass concentration of C18H32O2 = 1.6x10^-4 g/ml, Molar mass of C18H32O2 = 284 g/mol.

Unit factor from drops to ml is 72 drops = 1ml. Therefore, for every drop, n, given, there would be n drops (1ml/ 72drops). The problem tells that stearic acid was added to hexane and that the addition process was done three-time with different amounts of drops. Think of this as releasing a substance from a burette during titration. If we convert the drops into millimeters, we would have 20 drops (1ml/72drops)= 0.28 ml, 21 drops (1ml/72drops)= 0.29 ml, and 16 drops (1ml/72drops)= 0.22 ml. [We need these volumes to determine the mass of stearic acid from mass concentration given.]

Unknown informations are:

V (volume in ml) =?

The mole of stearic acid used =?

Strategy

To calculate the mole of stearic acid used, we need the mass of stearic acid from the mass concentration. To get this we need a volume. Notice that those volumes (drops) are not the same ( it is safe to say that there is an error in the readings, as they were done independently). Therefore, we would find two or three values whose difference is smaller ( there is a little error). Subtract the smaller number from the larger number till you get a smaller difference ( do this for all three values).

The set of numbers with the smallest difference is 0.29 - 0.28=0.014, our concordant value.

Solutions

Now we us this set of numbers, 0.29-0.28, to determine an average volume :

V = (0.29-0.28)/2 (ml)

V= 0.285 ml

Now we can calculate the mass of stearic acid from the mass concentration:

m = C*V; m is the mass, C is the concentration in g/ ml, and V is the volume in ml.

m = (1.64*10^-4 g/ml)*(0.285 ml)

m = 4.674*10^-5 g

The mole of stearic acid used:

n = m/MM l; n is the mole of stearic acid, m is the mass of stearic acid, and MM is the molar mass of stearic acid.

n = 4.674*10^-5 g (284 g/mol)

n = 1.3274*10^-3

How many molecules of stearic acid would there be if it was 1 mol of stearic acid?

1 mol = 6.02214*10^23 molecule

Therefore, a conversion fraction would be:

6.02214*10^23 molecule/ 1 mol

Solution

Molecules of stearic acid in 1 mol =

1.3274*10^-3 mol (6.02214*10^23 molecule/ 1 mol)

= 7.994*10^20 molecules in 1 mol of C18H16O2

Answer:

0.0736 M or 10.4 g/L

Explanation:

First we convert 4.550 g of Na₂SO₄ into moles, using the molar mass of Na₂SO₄:

Then we calculate the final volume of the solution:

Now we can proceed to calculate the concentration -in molarity- of the solution:

In g/L the concentration would be:

Answer:

The volume will be 568.89 mL.

Explanation:

Boyle's law says that "The volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure"

Boyle's law is expressed mathematically as:

Pressure * Volume = constant

or P * V = k

Gay-Lussac's law indicates that when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases. That is, the pressure of the gas is directly proportional to its temperature. Gay-Lussac's law can be expressed mathematically as follows:

[tex]\frac{P}{T}=k[/tex]

Where P = pressure, T = temperature, K = Constant

Finally, Charles's law indicates that as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases. In summary, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:

[tex]\frac{V}{T}=k[/tex]

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:

[tex]\frac{P*V}{T} =k[/tex]

Studying an initial state 1 and a final state 2, it is fulfilled:

[tex]\frac{P1*V1}{T1} =\frac{P2*V2}{T2}[/tex]

In this case:

Replacing:

[tex]\frac{960 mmHg*550 mL}{473K} =\frac{830 mmHg*V2}{423 K}[/tex]

Solving:

[tex]V2=\frac{423 K}{830 mmHg} *\frac{960 mmHg*550 mL}{473K}[/tex]

V2= 568.9 mL

The volume will be 568.89 mL.

Answer:

Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes.

Answer:

pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.32 ) = 6.32

Explanation:

Given 4.3 x 10⁻⁷M H₂CO₃ (Ka1 = 4.2 x 10⁻⁷ &  Ka2 = 4.8 x 10⁻¹¹)

Note: The Ka2 value for the 2nd ionization step is so small (Ka2 = 4.8 x 10⁻¹¹) It will be assumed all of the hydronium ions (H⁺) come from the 1st ionization step.  

1st Ionization step

                    H₂CO₃        ⇄   H⁺ + HCO₃⁻

C(initial)     4.3 x 10⁻⁷             0         0

ΔC                   -x                  +x        +x

C(final)      4.3 x 10⁻⁷ - x         x          x

Note: the 'x' value in this analysis can not be dropped as the Conc/Ka value is less than 10². In this case he C/Ka ratio* (4.3E-7/4.2E-7 ≈ 1)  is far below 10².

So, one sets up the equilibrium equation to be quadric and the x-value can be determined.

Ka1 = [H⁺][HSO⁻]/[H₂SO₃] = (x)(x)/(4.3 x 10⁻ - x) = x²/(4.3 x 10⁻⁷ - x) = 4.2 x 10⁻⁷

=>   x² = 4.2 x 10⁻⁷(4.3 x 10⁻⁷ - x)

=>   x² + 4.2 x 10⁻⁷x - 1.8 x 10⁻¹³ = 0              

      a = 1, b = 4.2 x 10⁻⁷, c = - 1.8 x 10⁻¹³

x = b² ± SqrRt(b² - 4(1)(-1.8 x 10⁻¹³ / 2(1) =  4.75 x 10⁻⁷

x = [H⁺] = 4.75 x 10⁻⁷

pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.4 ) = 6.4

______________________

* The Concentration/Ka-value is the simplification test for quadratic equations used in Equilibrium studies. If the C/Ka > 100 then one can simplify the C(final) by dropping the 'x' if used in this type analysis. However, if the C/Ka value is < 100 then the x-value must be retained and the solution is determined using the quadratic equation formula.

for ax² + bx + c = 0

x = b² ± SqrRt(b² - 4ac) / 2a

Answer:

Explanation:

Answer:

the rays strike at a low level in the polar region

Explanation:

okay so since the polar zones lie between 66.50 north or south the polar regions are always so cold is because strike the low parts

hope this helped!

Based on the rate of disappearance of HI, the rate of appearance of I₂ is 0.225 mol/L/s.

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.

From 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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Answer:

C

Explanation:

First there is no chemicals involved so cross out B and D. Wind turbines are made to create energy not to convert it so A is crossed out as well. The remaining answer is C.

The energy is transformed from mechanical to electrical when the blades are spinning, as shown.

Wind turbines are large fans that convert the kinetic energy of wind into electrical energy.

The blades run by winds and generate electricity.

They are helpful, but they are a threat to birds and bats.

Thus, the correct option is C, mechanical to electrical energy.

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