By examining data from distant stars, astronomers can determine
if a star is moving away from or toward Earth. Which of the
following pieces of data would be most helpful in determining
the motion of a star?
A The star gives off blue-white light.
B
The star gives off mainly radio waves and X-rays.
C
The light spectrum given off by the star is shifted toward the
red end.
.
D
The surface temperature of the star is approximately 10,000°
Celsius.

Answer:

If you add bromine water, an aqueous solution of bromine, to the test tubes, you can tell which is propene, the alkene. The bromine reacts with and saturates the double bonds in alkenes, and so decolourises.

please give brainly

Answer:

CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄

Explanation:

The question is missing but I think it must be about writing and balancing the equation.

Let's consider the unbalanced equation for the reaction that occurs when aqueous copper (II) sulfate reacts with aqueous potassium fluoride to produce  a precipitate of copper (II) fluoride (I fixed a mistake here) and aqueous potassium sulfate. This is a double displacement reaction.

CuSO₄(aq) + KF(aq) = CuF₂ + K₂SO₄

Since only K and F atoms are not balanced, we will get the balanced equation by multiplying KF by 2.

CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄

Answer:

Water acts as a base in the presence of a strong acid

Explanation:

Water,being an amphoteric compound, can act both as an acid and as a base.

In the presence of an acid , water acts as a base but in the presence of a base, water acts as an acid.

Answer:

Decay-the breakdown of dead plants..

Earth- thermal energy comes from deep inside...

Fires- these consume feul...

Explanation:

Answer:

Fires - These consume fuel and covert chemical energy stored in that fuel into thermal, light and sound energy

Decay - The breakdown of dead plants and animals produces thermal energy

Earth - Thermal energy comes from deep inside and is called geothermal energy

Explanation:

Fires, when you burn wood, you convert chemical energy from the wood into thermal (warmth from the fire), light (glow from the fire), sound (crackling sound of wood burning)

Decay - I can't explain that one to you but there are power plants that use decomposition to produce energy

Earth - Beneath the crust there is the mantle, which consists of molten rock which produces a lot of thermal energy. This can be seen in geysers, where the molten rock heats water and hot water can burst out of the surface. Applies to hot springs too

Answer:

20.2 amu.

Explanation:

Let A represent isotope ²⁰X

Let B represent isotope ²²X

From the question given above, the following data were obtained:

For Isotope A (²⁰X):

Mass of A = 20

Abundance (A%) = 90%

For Isotope B (²²X):

Mass of B = 22

Abundance (A%) = 10%

Relative atomic mass (RAM) =?

The relative atomic mass (RAM) of the element can be obtained as follow:

RAM = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]

RAM = [(20 × 90)/100] + [(22 × 10)/100]

RAM = 18 + 2.2

RAM = 20.2 amu

Thus, relative atomic mass (RAM) of the element is 20.2 amu

Answer:

hello your question is poorly written attached below is the complete question

answer : Kp = 4.75 * 10^-3

Explanation:

Kp = (76.4 * ( 50.3 )^2 )/ ((79.1)^2 * (80.6)^2 )

    = 193298.876 / 40646490.2116

    = 0.00475 ≈ 4.75 * 10^-3

attached below is the beginning part of the solution

Answer:

14.25g

Explination:

I found this answer on quizlet titled, "Chem Quizlet" by jamie_barbara

Answer:

B.

Explanation:

it's B because 4 x 2 is 8 and we all know 8 x 8 is 64. So the answer is B.

The equation that is correct if the volume of a block is 64 cm³ is 8 cm x 4 cm x 2 cm = 64 cm³. The correct option is B.

Volume is the space occupied by any three-dimensional object. The volume is also considered as the total weight of the object. The volume is calculated as mass is divided by the density.

A block will be a rectangle because it contains length, breadth, and height. The formula will be V = L x B x H

As take all the options, and multiply them, we can calculate the actual volume of the box;

5 cm x 5 cm x 5 cm = 125

8 cm x 4 cm x 2 cm = 64 cm3

5 cm + 5 cm + 5 cm = 15

8 cm + 4 cm + 2 cm = 14

So, the correct option will be B, 8 cm x 4 cm x 2 cm = 64 cm. All others are incorrect.

Thus, the correct option is B.  8 cm x 4 cm x 2 cm = 64 cm.

To learn more about volume, refer to the link:

https://brainly.com/question/1578538

#SPJ2

Answer:

The sample of __Ca___ contains the greatest number of atoms

Explanation:

As we know,

1 mole [tex]= 6.022*10^{23}[/tex] molecular entities (Can be atom, ions or molecules)

Number of atoms in 1.76 mole sample of Be

[tex]= 6.022*10^{23} *1.76\\= 1.059 * 10^{24}[/tex]

The sample of __Ca___ contains the greatest number of atoms

Answer:

496 g of Fe₂O₃.

Explanation:

The balanced equation for the reaction is given below:

4Fe + 3O₂ —> 2Fe₂O₃

From the balanced equation above,

4 moles of Fe reacted to produce 2 moles of Fe₂O₃.

Therefore, 6.20 moles of Fe will react to produce = (6.20 × 2)/4 = 3.1 moles of Fe₂O₃

Finally, we shall determine the mass of 3.1 moles of Fe₂O₃. This can be obtained as follow:

Mole of Fe₂O₃ = 3.1 moles

Molar mass of Fe₂O₃ = (56 × 2) + (3×16)

= 112 + 48

= 160 g/mol

Mass of Fe₂O₃ =?

Mass = mole × molar mass

Mass of Fe₂O₃ = 3.1 × 160

Mass of Fe₂O₃ = 496 g

Therefore, 496 g of Fe₂O₃ were produced from the reaction.

Answer:

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Answer:

C

Explanation:

Answer:

1) Activation energy  ( A )

2) Molar concentration of X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) ( C )

Explanation:

X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) ⇄ 2XZ

1) Activation energy Is decreased by the addition of a catalyst

while Equilibrium constant will Increase and other options will still remain unaffected

2)Molar concentration of X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) Is deceased when the volume of the reaction vessel is increased and equilibrium is reestablished at 298 K

while Number of molecules present will Increase

Answer:

2

Explanation:

WO2(s) + 2H2(g) -> W(s) + 2H2O(l)

Answer:

what I got was 0.8435160945347224 moles

solid carbon dioxide, iodine, arsenic, and naphthalene

Explanation:

Examples of substances that undergo sublimation

Examples of solids that sublime are dry ice (solid carbon dioxide), iodine, arsenic, and naphthalene (the stuff mothballs are made of).

Answer:

3 × 10⁴ kJ

Explanation:

Step 1: Write the balanced thermochemical equation

C₃H₈(g) + 5 O₂(g) ⟶ 3 CO₂(g) + 4 H₂O(g) ΔH = -2220 kJ

Step 2: Calculate the moles corresponding to 865.9 g of H₂O

The molar mass of H₂O is 18.02 g/mol.

865.9 g × 1 mol/18.02 g = 48.05 mol

Step 3: Calculate the heat produced when 48.05 moles of H₂O are produced

According to the thermochemical equation, 2220 kJ of heat are evolved when 4 moles of H₂O are produced.

48.05 mol × 2220 kJ/4 mol = 2.667 × 10⁴ kJ ≈ 3 × 10⁴ kJ

Answer:

The Lewis structure for the sulfate ion consists of a central sulfur atom with four single bonds to oxygen atoms. This yields the expected total of 32 electrons. Since the sulfur atom started with six valence electrons, two of the S-O bonds are coordinate covalent.

Explanation:

Then that means it has both.

Answer:

.0014 M/s ( (mol*L^-1 / s) )

Explanation:

Since the rate law of a zero order reaction is Rate = k[A]^0, the rate is .0014 * (1.65)^0 = .0014

Answer:

7. Option D

Explanation:

Solubility increases with the increase in temperature of the solution. It is so because the increase in temperature leads to increase in kinetic energy which then breaks the solute particles held together by intermolecular attractions.

Hence, option D is correct

Answer:

A mole ratio is ​the ratio between the amounts in moles of any two compounds involved in a chemical reaction.

Mole ratios are used as conversion factors between products and reactants in many chemistry problems.

Explanation:

Answer:

Yes.

Explanation:

Yes, this method is accurate just as the slow titration because in both type of titrations we want to measure the point at which the indicator change the colour of the solution. Both fast and slow titrations are the same in their function i.e. both tell us the point or the amount at which the indicator change the colour of the solution so we can conclude from this discussion that fast titration gives the same result just as the slow titration.

Answer:

Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited.

Explanation:

Answer:

50.4 mL

Explanation:

Step 1: Given data

Step 2: Convert the temperatures to Kelvin

We will use the following expression.

K = °C + 273.15

K = 15.0°C + 273.15 = 288.2 K

K = 30.0°C + 273.15 = 303.2 K

Step 3: Calculate the final volume occupied by the gas

We will use the combined gas law.

P₁ × V₁ / T₁ = P₂ × V₂ / T₂

V₂ = P₁ × V₁ × T₂/ T₁ × P₂

V₂ = 785.0 torr × 45.5 mL × 303.2 K/ 288.2 K × 745.0 torr = 50.4 mL

Answer:

C.

Explanation: