You are an astrophysicist and have discovered a new star. You use a spectrometer to read the absorption spectrum of the star. Based on the data below, what elements does the star contain?


A. H and He
B. H
C. He and Hg
D. H, He, and Hg

Answer: a for the first one , d for the second  one, b for the third one.

Explanation:

Answer:

A: Main sequence star.

B: White Dwarf.

C: Black hole.

Explanation:

Brainliest please.

The question is incomplete, The complete question is;

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. What experimental evidence led to the development of this atomic model from the one before it?

Answer:

A few of the positive particles aimed at a gold foil seemed to bounce back.

Explanation:

This model of the atom was proposed by Ernest Rutherford and was called the planetary model of the atom.

This model is based on an experiment using a gold foil on which alpha particles were focused. Most of the alpha particles passed through the foil. Some of the alpha particles were scattered at large angles and a few seemed to bounce back.

This led to the conclusion that the atom has a massive positive core around which electrons move as planets move around the sun.

Answer:

It is A

Explanation:

Answer:

B

Explanation:

The [tex]\rm \bold{F^1^-}[/tex] is the fluorine anion with 8 valence electrons. Hence, option B is correct.

An ion is defined as the atom with the change in the valence electrons by the loss or gain of electrons to complete the outer shell.

The ions with the gain of electrons result in a negative charge and are termed anions. The ions with a loss of electrons have a positive charge and are termed cations.

The F is the halogen atom of group 17 with 7 valence electrons. The ion formed for F requires 1 electron to complete its valence shell.

The ion [tex]\rm F^1^-[/tex] has a negative charge, which denotes it gains an electron and forms anion.

The gain of electrons results in the number of valence electrons being 8.

Thus, [tex]\rm F^1^-[/tex] is the fluorine anion with 8 valence electrons. Hence, option B is correct.

Learn more about ions, here:

https://brainly.com/question/1782326

Answer: synthesis

Explanation:

Answer:

Synthesis

Explanation:

Two compounds combine to produce one compound

Red blood cells are red because they contain Haemoglobin

Answer:

[OH⁻] = 0.002 M

Explanation:

The definition of pOH is similar to the definition of pH:

This means that with a given pOH value, the calculation of [OH⁻] is a matter of algebra:

To remove the logarithm we increase 10 by the power of the pOH:

Answer:The hydrogen bond is responsible for many of the anomalous physical and chemical properties of compounds of N, O, and F. In particular, intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group 16 hydrides that have much weakerhydrogen bonds

Hydrogen bonding is primarily responsible for the high ______ of water.

Answer:

It's C

Explanation:

cuz im goated

Answer:

24

Explanation:

Because atomic number is the number of protons.

Answer:

312g O₂ son necesarios, se producen 264g CO₂ y 135g H₂O

Explanation:

La combustión de butano para producir CO₂ y H₂O ocurre así:

C₄H₁₀ + 13/2O₂ → 4CO₂ + 5H₂O

Donde 1 mol de butano reacciona con 13 moles de oxígeno para producir 4 moles de dióxido de carbono y 5 moles de agua.

Para resolver este problema debemos convertir la masa de butano a moles y, usando la reacción balanceada, obtener cuánto se necesita de oxígeno y cuánto se produciría de dióxido de carbono y agua:

Moles butano -Masa molar: 58.12g/mol-:

87.0g * (1mol / 58.12g) = 1.50 moles

Moles y masa de oxígeno necesarias para la reacción -Masa molar: 32g/mol-:

1.50 moles C₄H₁₀ * (13/2 moles O₂ / 1 mol C₄H₁₀) = 9.75 moles * (32g/mol) =

312g O₂ son necesarios

Moles y masa de dióxido de carbono producidas -Masa molar: 44.01g/mol-:

1.50 moles C₄H₁₀ * (4 moles CO₂ / 1 mol C₄H₁₀) = 6 moles * (44.01g/mol) =

264g CO₂ se producen

Moles y masa de agua producidas -Masa molar: 18.015g/mol-:

1.50 moles C₄H₁₀ * (5 moles H₂O / 1 mol C₄H₁₀) = 7.5 moles * (18.015g/mol) =

135g H₂O se producen

Answer:

Explanation:

I gave this formula as

What you should get - what you got

---------------------------------------------------   * 100

What you should get

Suppose you are talking about the specific heat of copper and you did a lab and did it fairly well and the specific heat came out to be 0.33

That's what you got, 0.33

What you should get is 0.35 according to the table you've given us.

% error = 0.35 - 0.33

                -------------- * 100

                      0.35

% error = 0.02 * 100/ 0.35

% error = 2/0.35

% error = 5.71

Now here is the really hard part. You have to decide what a positive error is and what a negative error.

A positive error using this formula means you are too low.

A Negative error means that you are too high, just the opposite of what you might think.

Can you show us the experimental value?

So basically, the accepted value would be under the Specific heat capacity of metal (e.g. 0.90, 0.35, 0.44, 0.12).

Your experimental value would be the specific heat capacity that you got from the lab.

You would first substract the experimental value from the accepted value

[tex]accepted \: value - experimental \: value [/tex]

and then you would divide the result by the experimental value

[tex]result \div experimental \: value[/tex]

and then, you would multiply the result of that by a hundred to get your percentage

[tex]result \times 100 = \% \: error[/tex]

//

The image shown is an example.

0.90 is our accepted value.

0.88 is our experimental value.

The overall percentage error I got is %2.27

Answer:

mineral acids are obtained from one or more inorganic compounds which is a compound that lacks carbon and hydrogen bonds. Inorganic compound examples include water and carbon dioxide. Something all mineral acids do is form hydrogen ions and the joined together bases when it is dissolved  in water.

Explanation:

Answer:

gases are able to spread out and fill whatever container they are in because they do not have. a definite shape their molecules are not tightly packed so they can cover over a vast area like our atmosphere.

Cl2 = 70.9 g/mol

=

[tex]21.4 \: mol \times \frac{70.9 \: g}{1 \: mol} = 1517.26 \: g[/tex]

Answer:

c. lakes freeze from the botton up

Answer:

I'm pretty sure the net force is 200 N and the direction of motion is left

Explanation:

500 - 300 = 200 and more force is coming from and pulling toward the left.

Answer:

Isotopes

Explanation:

Isotopes are atoms of the same element that contain an identical number of protons, but a different number of neutrons. Despite having different numbers of neutrons, isotopes of the same element have very similar physical properties.

Answer:

pH = 11.30

Explanation:

pH is defined as -log [H⁺]

To find [H⁺] from [OH⁻] -Concentration of hydroxide ion-, we must use the equilibrium of water:

H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)

Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]

[H⁺] = 1x10⁻¹⁴ / [OH⁻]

[H⁺] = 1x10⁻¹⁴ / 2x10⁻³M

[H⁺] = 5x10⁻¹²M

pH = -log (5x10⁻¹²M)

Answer:

it travels through the veins

Answer:

0.25L or 250Ml

Explanation:

I am not that good but as far as my calculations this must be the answer

Answer:

The mass of 42.3 moles of potassium sulfate is 7,371.1557 grams

Explanation:

Potassium sulfate K₂SO₄ which is also known as sulphate of potash is a water soluble common component of fertilizer

The molar mass of potassium sulfate, M = 174.259 g/mol

The given number of moles of potassium sulfate, n = 42.3 moles

The mass, 'm', of a given number of moles of potassium sulfate, 'n', is given as follows;

m = n × M

Therefore, we have;

The mass, 'm', of 42.3 moles of potassium sulfate is found by plugging in the values for 'M', and 'n', in the above equation as follows;

m = 42.3 moles × 174.259 g/mol = 7,371.1557 grams

The mass of 42.3 moles of potassium sulfate, m = 7,371.1557 grams.

Answer:

We know that, composition of HNO3 is Hydrogen, Nitrogen and oxygen. Total number of atoms = 3+1+1=5 atoms are present in 1 molecule of HNO3.

Answer:

the creation of oxygen.

Explanation:

Answer:

Final temperature = 152.57K,

Pressure = 0.6907 bar.

dT/dt = - 1,151 K/s.

Explanation:

The first thing to do here is to write out the equation for mass balance as given below:

dN/dt = N -------------------------------------------------------------------------------------------(1).

N = P/T, then, substitute the values given in the question into:

d[p/T]/ dt = [- 4.5/28 × 8.314]/0.15 = - 8.9 × 10⁻⁵ bar/K.s.

Thus, there is the need to integrate, Integrate [p/T]f = 10/320 - 8.9 × 10⁻⁵ bar/K.s. ------------------------------------(2).

NB; fT = final temperature, fP = final pressure and iT = initial temperature.

Also, [ fT]³⁰/₈.₃₁₄/ [fP] = [iT]³⁰/₈.₃₁₄/ Pi] = [ 320]³⁰/₈.₃₁₄/ 10.

Therefore, [fT]³⁰/₈.₃₁₄ = 109.52 × 10⁶.

Final temperature=  [fP]³⁰/₈.₃₁₄ × 169.05.

Note that fP/ [fP]³⁰/₈.₃₁₄ × 169.05 = 10/320 - 8.9 × 10⁻⁵.

Therefore, [fP]¹ ⁻ ³⁰/₈.₃₁₄ = 0.7651.

Hence, Final temperature = 152.57K,

Pressure = 0.6907 bar

dT/ dt = N[RT]² / Cv . PV.

R = 30 - 8.314 = 21.86 J/mol K.

Then, the rate of change of the gas temperature at this time = dT/dt = - 1,151 K/s.

Answer:

carbon monoxide

Explanation:

I'm not sure but I think

Answer:

2 electron are transferred when Be and O bond formed

Answer:

2 is the answer:)))))))))

Answer:

Of earthquakes

Explanation:

Answer:

That's simple it's the caca of 54 32 x (5) b ÷ 5683jvl done so your answer is 0