All categories

3 years ago

Which statement accurately describes binary star systems?

Chemistry

2 answers:

Nata [24]3 years ago

8 0

Answer:

d!!!!!

Explanation:

Yakvenalex [24]3 years ago

4 0

Answer:

The correct answer is D.They have stars that may appear to wobble.

Explanation:

Binary star - Wikipediaen.wikipedia.org › wiki › Binary_star

''Astronomers have discovered some stars that seemingly orbit around an empty space. Astrometric binaries are relatively nearby stars which can be seen to wobble around a point in space, with no visible companion. The same mathematics used for ordinary binaries can be applied to infer the mass of the missing companion''

-Wikipediaen.wikipedia.org › wiki › Binary_star

-Edge 2021

might be a lil late but YW

You might be interested in

What variables are considered when forecasting weather

saveliy_v [14]

There are lots of variables.
1. relative humidity
2. dew point temperature
3. air temperature
4. wind speeds
5. vapor pressure
6. latitude and longitude
7. orrographic lift (surface type)

there are probably more, but hope this helped! :)

4 0

3 years ago

What kind of change took place when the magnesium was heated?

Dmitrij [34]

Answer:

You can see that it is an endothermic reaction or heat is being absorbed for the change from magnesium to magnesium oxide. So it is an endothermic reaction. So these are the four reasons why we can say that burning of magnesium ribbon in the air is considered a chemical change.

Explanation:

hope it help

6 0

3 years ago

Read 2 more answers

Which accurately represents these building blocks of matter from the smallest to the largest? atom → molecule or compound molecu

Natali5045456 [20]

Answer:

The awnser is A.

Explanation:

I got it right on edgenuity. If im wrong sorry ;-;

5 0

3 years ago

Read 2 more answers

The element boron exists in nature as two isotopes: 10B has a mass of 10.0129 u, and 11B has a mass of 11.0093 u. The average at

Shalnov [3]

Answer:

Percentage abundance of B 10 is = 20 %

Percentage abundance of B 11 is = 80 %

Explanation:

The formula for the calculation of the average atomic mass is:

$Average\ atomic\ mass=(\frac {\%\ of\ the\ first\ isotope}{100}\times {Mass\ of\ the\ first\ isotope})+(\frac {\%\ of\ the\ second\ isotope}{100}\times {Mass\ of\ the\ second\ isotope})$

Given that:

Since the element has only 2 isotopes, so the let the percentage of first be x and the second is 100 -x.

For first isotope, B 10:

% = x %

Mass = 10.0129 u

For second isotope, B 11:

% = 100 - x

Mass = 11.0093 u

Given, Average Mass = 10.81 u

Thus,

$10.81=\frac{x}{100}\times {10.0129}+\frac{100-x}{100}\times {11.0093}$

$10.0129x+11.0093\left(100-x\right)=1081$

Solving for x, we get that:

x = 20 %

Thus percentage abundance of B 10 is = 20 %

Percentage abundance of B 11 is = 100 - 20 % = 80 %

8 0

3 years ago

Read 2 more answers

The solubility of KCl is 3.7 M at 20 °C. Two beakers each contain 100. mL of saturated KCl solution: 100. mL of 4.0 M HCl is add

JulijaS [17]

Answer:

a)The Ksp was found to be equal to 13.69

Explanation:

Terminology

Qsp of a dissolving ionic solid — is the solubility product of the concentration of ions in solution.

Ksp however, is the solubility product of the concentration of ions in solution at EQUILIBRIUM with the dissolving ionic solid.

Note that if Qsp > Ksp , the solid at a certain temperature, will precipitate and form solid. That means the equilibrium will shift to the left in order to attain or reach equilibrium (Ksp).

Step-by-step solution:

To solve this:

#./ Substitute the molar solubility of KCl as given into the ion-product equation to find the Ksp of KCl.

#./ Find the total concentration of ionic chloride in each beaker after the addition of HCl. We pay attention to the amount moles present at the beginning and the moles added.

#./ Find the Qsp value to to know if Ksp is exceeded. If Qsp < Ksp, nothing will precipitate.

a) The equation of solubility equilibrium for KCL is thus;

KCL_(s) ---> K+(aq) + Cl- (aq)

The solubility of KCl given is 3.7 M.

Ksp= [K+][Cl-] = (3.7)(3.7) =13.69

The Ksp was found to be equal to 14.

In pure water KCl

Ksp =13.69 KCl =[K+][Cl-]

Let x= molar solubility [K+],/[Cl-] :. × , x

Ksp =13.69 = [K+][Cl-] = (x)(x) = x²

x= √ 13.69 = 3.7 M moles of KCl requires to make 100mL saturated solutio

37M moles/L

The Ksp was found to be equal to 14.

4.0 M HCl = KCl =[K+][Cl-]

Let y= molar solubility :. y, y+4

Ksp =13.69= [K+][Cl-] = (y)(y*+4)

* - rule of thumb

Ksp =13.69= [K+][Cl-] = (y)(y*+4)= y(4)

13.69=4y:. y= 3.42 moles/100mL

y= 34.2moles/L

8 M HCl = KCl =[K+][Cl-]

Let b= molar solubility :. B, b+8

Ksp =13.69= [K+][Cl-] = (b)(b*+8)

* - rule of thumb

Ksp =13.69= [K+][Cl-] = (b)(b*+8)= b(8)

13.69=8b:. b= 1.71 moles/100mL

17.1 moles/L

Therefore in a solution with a common ion, the solubility of the compound reduces dramatically.

8 0

3 years ago

Read 2 more answers