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Answer:

The correct answer is A

Explanation:

A radio telescope is used to detect, collect and focus radio waves from distant objects in the sky or space. While a compound telescope, by design, can both refract and reflect waves. A reflection telescope uses curved mirrors to reflect light to form an image. A refraction telescope forms an image using a lens as its objective.

From the above definitions, it can be deduced that option A is the correct answer.

Answer:

29

Explanation:

since protons are a constant and unique characteristic of an element it's considered as he atomic number of that element.

Answer: The rate of diffusion of methane is 100 cc.

Explanation:

Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of the molar mass of the gas. The equation for this follows:

[tex]\text{Rate}=\frac{1}{\sqrt{M}}[/tex]       .....(1)

where M is the molar mass of the gas

We are given:

[tex]Rate_{X}=50cc[/tex]

[tex]M_{X}=4\times M_{CH_4}[/tex]

Since the molar mass of methane = 16 g/mol

Using equation 1:

[tex]\frac{Rate_{CH_4}}{Rate_{X}}=\sqrt{\frac{M_X}{M_{CH_4}}}[/tex]

Putting values in above equation, we get:

[tex]\frac{Rate_{CH_4}}{50cc}=\sqrt{\frac{(4\times 16)}{16}}\\\\Rate_{CH_4}=50\times \sqrt{4}\\\\Rate_{CH_4}=50times 2=100cc[/tex]

Hence, the rate of diffusion of methane is 100 cc.

The first diagram shows the covalent bonds most likely form in a phosphorous trichloride molecule. Hence, option A is correct.

Covalent bonds can be polar or nonpolar depending on the electronegativity difference between the atoms involved. In a nonpolar covalent bond, the electrons are shared equally between the atoms. In a polar covalent bond, the electrons are shared unequally.

Phosphorus trichloride (PCl₃) is a covalent compound that consists of one phosphorus atom and three chlorine atoms. The three chlorine atoms are located in a plane that is perpendicular to the phosphorus atom, forming an equilateral triangle with bond angles of 120°.

The molecule has a trigonal pyramidal shape, with the phosphorus atom at the apex and the three chlorine atoms at the base of the pyramid. The fourth hybridized orbital of phosphorus contains a lone pair of electrons that is located above the trigonal plane, giving the molecule a distorted tetrahedral geometry.

Thus, option A is correct.

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Answer:

blue

Explanation:

Answer:

Follow these steps.

1. Fill the matchbox with pebbles. Weigh the matchbox with the pebbles inside. Record that weight.

2. Tie the string to the box. Allow the string to hang over the edge of the table.

3. Tie the other end of the string to a corner of the plastic bag, leaving an opening to put in coins.

4. Add coins one by one until the box is pulled off the table.

5. Count and record the number of coins and the weight of the bag with the coins in it.

6. Lay the round sticks on the table about 1 inch apart and about 2 inches from the edge of the table.

7. Put the matchbox on the rollers farthest from the edge of the table.

8. Now add coins one by one to the bag until the box is pulled off the table.

9. Count and record the number of coins and the weight of the bag with the coins in it.

10. Repeat the experiment. Determine your margin of error if your results vary. For accuracy, repeat the experiment if desired.

11. Using the equation for the coefficient of friction in the text above, determine the coefficient of friction for the matchbox in each experiment. Include this data in your summary.

Explanation:

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Answer:Follow these steps.

1. Fill the matchbox with pebbles. Weigh the matchbox with the pebbles inside. Record that weight.

2. Tie the string to the box. Allow the string to hang over the edge of the table.

3. Tie the other end of the string to a corner of the plastic bag, leaving an opening to put in coins.

4. Add coins one by one until the box is pulled off the table.

5. Count and record the number of coins and the weight of the bag with the coins in it.

6. Lay the round sticks on the table about 1 inch apart and about 2 inches from the edge of the table.

7. Put the matchbox on the rollers farthest from the edge of the table.

8. Now add coins one by one to the bag until the box is pulled off the table.

9. Count and record the number of coins and the weight of the bag with the coins in it.

10. Repeat the experiment. Determine your margin of error if your results vary. For accuracy, repeat the experiment if desired.

11. Using the equation for the coefficient of friction in the text above, determine the coefficient of friction for the matchbox in each experiment. Include this data in your summary.

Explanation:

The points on the y-intercepts are (0,y) whereas the point on the x-intercept are (x,0). Here the y-intercept of the function f(x) = -x + 2 is 2.

When the line touches the y-axis, we can say that these are y-intercepts. The y-intercept can be found out when x = 0. This represents the point at which the graph crosses through the y-axis. The y-intercept can also be referred as y-value.

In order to find the intercepts of any function, we must find the coordinates of the point where the function intersects the x and y axis. This can also be done by equating the independent or dependent variable value as 0 and then finding out the other value.

Here the given function is:

f(x) = -x + 2

When we put x = 0, then

f(x) = -0 + 2 = 2

Thus the y-intercept is 2.

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Answer:

The reactivity order reflects both the strength of the C-X bond and the stability of X(-) as a leaving group and leads to the general conclusion that alkyl iodides are the most reactive members of this functional class

Answer:

32.4grams

Explanation:

Density of a substance can be calculated as follows:

Density = mass ÷ volume

According to this question, the density of aluminum is 2.7g/cm³ while its volume is 12 cm³. The mass of aluminum is therefore,

2.7 = m/12

m = 12 × 2.7

m = 32.4grams.

The mass of aluminum is 32.4grams

the pressure of the gas increases

Answer:

The number of collisions of gas particles increases.

Explanation:

Just took the test!!!

Answer:

[tex]304cm = 3.04m \\ 67kg = 67000g[/tex]

Explanation:

[tex]100cm \: = 1m \\ 304cm = x \\ use \: \: cross \: multipication \\ 100x = 304 \\ \frac{100x}{100} = \frac{304}{100} \\ x = 3.04m[/tex]

-------------------------------------------------

[tex]1kg = 1000g \\ 67kg = x \\ \\ use \: cross \: \: multipication \\ 1x = 67 \times 1000 \\ x = 67000g[/tex]

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Have a nice day!

Answer:

esfsef

Explanation:

esfsefseF

Answer:

The correct answer would be - 13.0975 ounces.

Explanation:

We know that brass is made up of zinc and copper. The copper part of the brass is approximately around 50 to 70% and the remaining is the zinc part.

Given:

Zinc percentage in a brass = 35%

copper percentage would be - 65% (100 - 35 = 65)

Weight of the brass metal bar = 20.15 ounce

ounces of copper are in the bar = ?

Solution:

The weight of the copper in the brass metal in ounces-

= weight of brass* percentage of copper/100

= 20.15*65/100

= 13.0975 ounces of copper.

2nd method =

The weight of the zinc in the brass metal in ounces-

= weight of brass* percentage of zinc/100

= 20.15*35/100

= 7.0525

The weight of the copper = total weight - weight of zinc

= 13.0975 ounces of copper.

Answer: sodium sulfide

Answer: The amount of heat absorbed is [tex]36.0\times 10^3Cal[/tex]

Explanation:

Few processes involved are:

(1): [tex]H_2O (s) (0^oC, 273K) \rightleftharpoons H_2O(l) (0^oC,273K)[/tex]

(2): [tex]H_2O (l) (0^oC, 273K) \rightleftharpoons H_2O(l) (100^oC,373K)[/tex]

(3): [tex]H_2O (l) (100^oC, 373K) \rightleftharpoons H_2O(g) (100^oC,373K)[/tex]

Calculating the heat absorbed for the process having same temperature:

[tex]q=m\times \Delta H_{(f , v)}[/tex] ......(i)

where,

q is the amount of heat absorbed, m is the mass of sample and is the enthalpy of fusion or vaporization

Calculating the heat released for the process having different temperature:

[tex]q=m\times C_{s,l}\times (T_2-T_1)[/tex] ......(ii)

where,

[tex]C_{s,l}[/tex] = specific heat of solid or liquid

[tex]T_2\text{ and }T_1[/tex] are final and initial temperatures respectively

We are given:

[tex]m=50.0g\\\Delta H_{fusion}=80Cal/g[/tex]

Putting values in equation (i), we get:

[tex]q_1=50.0g\times 80Cal/g\\\\q_1=4000Cal[/tex]

We are given:

[tex]m=50.0g\\C=1.00Cal/g^oC\\T_2=100^oC\\T_1=0^oC[/tex]

Putting values in equation (i), we get:

[tex]q_2=50g\times 1Cal/g^oC\times (100-0)\\\\q_2=5000Cal[/tex]

We are given:

[tex]m=50.0g\\\Delta H_{vap}=540Cal/g[/tex]

Putting values in equation (i), we get:

[tex]q_3=50.0g\times 540J/g\\\\q_3=27000Cal[/tex]

Calculating the total amount of heat released:

[tex]Q=q_1+q_2+q_3[/tex]

[tex]Q=[(4000)+(5000)+(27000)]Cal=36000Cal=36.0\times 10^3Cal[/tex]

Hence, the amount of heat absorbed is [tex]36.0\times 10^3Cal[/tex]

Answer:

C. 3.37 x 10^-19 J

Explanation:

Answer:

Phenol is more acidic than cyclohexanol and acyclic alcohols because the phenoxide ion is more stable than the alkoxide ion. ... But in a phenoxide ion, the negative charge is delocalized over the benzene ring. Phenoxide ion is therefore resonance stabilized.

Answer:

Phenol is more acidic than cyclohexanol and acyclic alcohols because the phenoxide ion is more stable than the alkoxide ion. ... But in a phenoxide ion, the negative charge is delocalized over the benzene ring. Phenoxide ion is therefore resonance stabilized.

Explanation:

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Answer:

Helium atom

Explanation:

For the RTGs flown by the United States, the radioisotope has been some chemical form of plutonium-238 (238Pu or Pu-238). Plutonium-238 decays primarily by the emission of an alpha particle (a helium atom without its electrons).

Answer:

The more polar the molecules, the stronger the force. The more hydrogen in the molecule, the stronger the force.

Explanation:

I hope this helps and please ask if you need further help!

Answer:

A

Explanation:

did that on my test

CH3OH IS MOLECULES OF ALCOHOL

Answer:

a. Ksp = 4s³

b. 5.53 × 10⁴ mol³/dm⁹

Explanation:

a. Obtain an expression for the solubility product of AB2(S),in terms of s.

AB₂ dissociates to give

AB₂ ⇄ A²⁺ + 2B⁻

Since 1 mole of AB₂ gives 1 mole of A and 2 moles of B, we have the mole ratio as

AB₂ ⇄ A²⁺ + 2B⁻

1 : 1 : 2

Since the solubility of AB₂ is s, then the solubility of A is s and that of B is 2s

So, we have

AB₂ ⇄ A²⁺ + 2B⁻

[s]        [s]    [2s]

So, the solubility product Ksp = [A²⁺][B⁻]²

= (s)(2s)²

= s(4s²)

= 4s³

b. Calculate the Ksp of AB₂, given that solubility is 2.4 × 10³ mol/dm³

Given that the solubility of AB is 2.4 × 10³ mol/dm³ and the solubility product Ksp = [A²⁺][B⁻]² = 4s³ where s = solubility of AB = 2.4 × 10³ mol/dm³

Substituting the value of s into the equation, we have

Ksp = 4s³

= 4(2.4 × 10³ mol/dm³)³

= 4(13.824 × 10³ mol³/dm⁹)

= 55.296 × 10³ mol³/dm⁹

= 5.5296 × 10⁴ mol³/dm⁹

≅ 5.53 × 10⁴ mol³/dm⁹

Ksp = 5.53 × 10⁴ mol³/dm⁹

Answer:

56.2

Explanation:

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Answer:

A

Explanation:

i had to answer this question a few weeks ago

Answer:

molecules

Explanation:

they are molecule

Answer: There are various indicators like litmus paper, phenolphthalein, universal indicator etc. that changes its colour to show the difference between acid and alkali.

Answer:

H2

Explanation:

(l) means liquid

(s) means solid

(g) means gaseous

I hope this helped [:

Answer:

faulse

Explanation:

this is an example of a change in proporties