Two airplanes are flying in the sky in such a way that the gravitational attractions between them decreases. The planes must be flying:
A.
away from each other.
B.
next to each other at the same speed.
C.
towards each other.
D.
faster than the speed of sound.

Answer:

11.4

Explanation:

Density = Mass / Volume

Density = 35.4 / 3.11

Density = 11.38263666

As there are more number of digits after the decimal, you can round it to 3 significant figure.

Now, your value will be:

Density = 11.4

Answer:

period is a horizontal row of the periodic table. There are seven periods in the periodic table, with each one beginning at the far left.

Explanation:

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In model periodic table the atoms are arranged wrt atomic number, there chemical behaviour, and properties.

The horizontal rows of periodic table are known as periods.

The vertical line of periodic table are knows as groups.

Na3PO4*12H2O + BaCl2*2H2O = Ba3(PO4)2 + NaCl + H2O

add barium chloride to your Na3PO4.12H2O a white precipitate of Ba3(PO4)2 will be formed wrt salt(NaCl) and water(H20) if Na3PO4.12H2O. will be there.

Answer: It is causing erosion, landslides, and craters. If this keeps up the ice in the artic will eventually be gone

Explanation:

1 becasuevof one vvalence shell

Answer:

The correct answer is MgCO₃.5H₂O.

Explanation:

Based on the given information,

The mass of hydrate of magnesium carbonate given is 15.67 grams, and the mass of anhydrous magnesium carbonate given is 7.58 grams.

Now the mass of water will be,

= 15.67 grams – 7.58 grams

= 8.09 grams

The molecular mass of magnesium carbonate is 84.32 grams, the moles of MgCO₃ can be determined by using the formula,

Number of moles = Mass/Molecular mass

Moles of MgCO₃ = 7.58/84.32

= 0.0898 moles

Similarly, the number of moles of water will be,

Moles of H₂O = 8.099/18.02

= 0.4489 moles

After getting the values, there is a need to choose the smaller value and use it to divide both the values to get the ratio,

MgCO₃ = 0.0898/0.0898 = 1

H₂O = 0.4489/0.0898 = 4.9 or 5

Thus, the molecular formula for the hydrate will be MgCO₃.5H₂O.

Answer:

I think it's 1.D

2.C

3.C

my apologies if it's incorrect

Answer:

The correct answer is 40.7 grams.

Explanation:

Based on the given information, the volume of copper sulfate added to the solution is 255 ml or 0.255 L. The molarity of copper sulfate is not given, so let us consider it to be 1 M, which can also be written as 1 moles per liter.

The moles of copper sulfate can be determined by using the formula,

Moles = Molarity * Volume in Liters

Moles of CuSO4 = 1 moles/Liter * 0.255 L

Moles of CuSO4 = 0.255 moles

The mass of CuSO4 added in the solution will be,

Mass of CuSO4 = Moles * Molecular mass

= 0.255 moles * 159.609 grams per mole

= 40.7 grams.

Answer:

83.3 L

Explanation:

Step 1: Given data

Capacity of the wine barrel (V): 22.0 gal

Step 2: Calculate how many liters of wine can be held in the barrel

To calculate the number of liters of wine that can be held in the barrel, we need to convert 22.0 gal to liters. We will use the conversion factor 1 gal = 3.79 L.

22.0 gal × 3.79 L/1 gal = 83.3 L

Answer:

Explanation:

How many mols do you have?

1 mol = 6.02 * 10^23 atoms

x mol = 6.25 * 10 ^32 atoms

1/x = 6.02*10^23 / 6.25 * 10^32        Cross multiply

6.02 * 10^23 * x = 1 * 6.25 * 10^32    Divide by 6.02 * 10^23

x = 6.25 * 10*32/ 6.02 ^10^23

x = 1.038 * 10^9 mols which is quite large.

Find the number of grams. (Use the value for copper on your periodic table. I will just use an approximate number.)\

1 mol of copper = 63 grams.

1.038 * 10^9 mols of copper = x

1/1.038 * 10^9 = 63/x         Cross multiply

x = 1.038 * 10^9 * 63

x = 6.54 * 10^10 grams of copper.

Answer:

Veins

Explanation:

Veins carry blood to the heart while arteries carry away from the heart

Explanation:

that both the plastic & balloon have the same charge

Answer:

Pure water contains no ions.  TRUE

Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions.  TRUE

Explanation:

This is the equilibrium for pure water:

2H₂O  ⇄  H₃O⁺  +  OH⁻          Kw

We see that pure water has no Ions. Pure water can not conduct electricity.

Generally ionized water comes from the water tap.

Another feature of pure water is pH.

Definetely pH of pure water is : 7

As pH = 7, [H₃O⁺] = 1×10⁻⁷

Then, [OH⁻] = 1×10⁻⁷

This is reazonable because Kw is 1×10⁻¹⁴ and Kw = [H₃O⁺] . [OH⁻]

In conclussion:

Pure water contains no ions.  TRUE

Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions.  TRUE

Pure water contains larger amounts of hydroxide [OH-] than hydronium [H3O+] ions.  FALSE

Pure water is an electrolyte. FALSE

Pure water contains smaller amounts of hydroxide [OH-] than hydronium [H3O ] ions. FALSE

Answer:

molecules take up more space

Answer:

It would test positive.

Answer:

Decomposition of normal salt ( sodium chloride )

Formation of water from hydrogen peroxide.

Combustion of propane

e.t.c

Answer:

The correct answer is 1.21 L.

Explanation:

Based on the given information, the reaction will be,

CS2 (l) + 3Cl2 (g) ⇒ CCl4 (l) + S2Cl2 (l)

By using the standard values of the substances, the standard enthalpy of the reaction is,

ΔH° = [(-139.5) + (-58.5) – 0 – (87.3)] kJ/mol

= -285.3 kJ/mol

The amount of heat evolved for 3 moles of chlorine reacted us 285.3 kJ.

Now the number of moles of chlorine needed to react to produce 5.00 kJ is,

= 5.00 kJ × 3 mol Cl2/285.3 kJ

= 0.0526 mol Cl2

Now the volume of chlorine gas at 27degree C and 812 mmHg will be,

Volume = 0.0526 mol Cl2 × 0.0821 Latm/mol K × 300 K/ 1.07 atm

= 1.21 L

Answer:

An increase in pressure would cause less volume and vice versa. They are inversely proportional.

Explanation:

This is due to Boyle's Law (and because an increase in pressure would increase the force on the container, however, if it's a closed container, it would burst)

Feel free to mark it as brainliest :D

Answer:

The original concentration is "35 mg/ml".

Explanation:

According to the question,

The solution is diluted,

= 1:50

The initial volume,

V1 = 1 ml

Final concentration,

= 0.07 mg

then,

The final volume,

V2 = 500 ml

As we know,

⇒ [tex]V_1N_1=V_2N_2[/tex]

or,

⇒ [tex]N_1=\frac{V_2N_2}{V_1}[/tex]

On substituting the values, we get

⇒       [tex]=\frac{500\times 0.07}{1}[/tex]

⇒       [tex]=\frac{35}{1}[/tex]

⇒       [tex]=35 \ mg/ml[/tex]

A 0.07 mg/mL BHL solution was prepared by performing a 1:500 dilution on a 35 mg/mL solution.

A 1:500 dilution was carried out to prepare a 0.07 mg/mL BHL solution. We can find the concentration of the initial solution using the dilution rule.

It is an equation that relates the concentration and volume of a concentrated and a dilute solution. The mathematical expression is:

C₁ × V₁ = C₂ × V₂

where,

C₁ = C₂ × (V₂/V₁)

C₁ = 0.07 mg/mL × (500/1) = 35 mg/mL

A 0.07 mg/mL BHL solution was prepared by performing a 1:500 dilution on a 35 mg/mL solution.

Learn more about dilution here: https://brainly.com/question/1615979

Answer:

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im 100% sure

Explanation:

Answer:

1.22 J/g.°C

Explanation:

Step 1: Given data

Step 2: Calculate the specific heat of the metal (c)

A metal absorbs heat and, as a consequence, its temperature increases. We can calculate its specific heat using the following expression.

c = Q / m × ΔT

c = 570.4 J / 17.5 g × 26.8 °C = 1.22 J/g.°C

Explanation:

Respuesta: La masa atómica del carbono (C) es 12 g/mol; para el oxígeno (O) es de 16 g/mol. Esto significa que 6.022 x 1023 átomos de carbono pesan 12 gramos. Según esto, el peso molecular del CO2 es: 12 g/mol [C] + 2 x 16 g/mol [O2] = 44 g/mol

Answer:

If you want to separate black grapes from the mixture of black and green grapes, then you will simply pick black grapes using your hands from the mixture. In this way you are actually using handpicking separation method.

Explanation:

Answer:

This combination can make a buffer

Explanation:

A buffer is defined as an aqueous mixture of a weak acid and its conjugate base, or vice versa.

In the problem, HF is a weak acid, and its conjugate base is F⁻.

When NaOH reacts with HF, F⁻, Na⁺ and H₂O are produced as follows:

NaOH + HF → F⁻ + Na⁺ + H₂O

As there are initially 0.2mol of HF and 0.1mol NaOH, after the reaction you will have:

0.1mol HF and 0.1mol F⁻. As both, the weak acic and the conjugate base are present:

Answer:

24.24 g

Explanation:

First we calculate how many moles are there in 300 mL of a 0.234 M solution, using the definition of molarity:

Converting 300 mL to L ⇒ 300 mL / 1000 = 0.300 L

Then we convert 0.78 moles of NH₄F into grams, using its molar mass:

Answer:17.65 or 18 L

Explanation: