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3 years ago

When does a star reach equilibrium?

2 answers:

5 0

Actually, that does not happen until the protostar becomes a star when nuclear ignition starts and is maintained. It takes awhile for new star to go through its T-Tauri stage and settle down on the main sequence.

A STAR does not reach hydrostatic equilibrium until it on the main sequence. Otherwise, it would remain a brown dwarf with not enough mass to to maintain nuclear fusion for more than 3,000 to 10,00 years.

Nata [24]3 years ago

4 0

Answer:

The correct answer is when gravity is balanced by the outward force of nuclear fusion hopefully this helps!

You might be interested in

an element in group two has two valence electrons. When forming a chemical bond it will most likely (gain, lose, share, or not r

Charra [1.4K]

Lose electrons - electrons want to fill their outer valence shell, so sometimes instead of gaining it is easier to lose some and have a filled outer shell

3 0

3 years ago

What does the periodic table have in common with a calendar?

Angelina_Jolie [31]

Answer:

Calendar and periodic table both have repetitive patterns.

Explanation:

In calendar the days are arranged and divided into weeks whereas in the periodic table the elements are arranged in increasing atomic number and divided into groups

5 0

3 years ago

Suppose you are testing the buoyancy of different objects. Study the table and choose the object with the greatest buoyant force

ehidna [41]

The correct answer is 7.8

7 0

3 years ago

Which of the following 0.300 M solutions would contain the highest concentration of potassium ions?

mojhsa [17]

Here is a list of 0.300 M solutions that you can consider to select which has the highest concetration of potassium ions:

Select one:

a. potassium oxide

b. potassium phosphate

c. potassium hydrogen carbonate

d. potassium hypochlorite

e. potassium iodide

Answer:

Option b. potassium phosphate

Explanation:

First, you must write the chemical formula of each one of the potasssium compounds. Then, assume all the compounds ionize 100%.

Since all the solutions have the same concentrations, by assuming 100% ionization, the ionization equations will show which one produces the highest number of potassium ions, K⁺¹, and that is the solution with the highest concentration of such ions.

1. Chemical formulae

Compound Formula

a. potassium oxide K₂O

b. potassium phosphate K₃PO₄

c. potassium hydrogen carbonate KHPO₃

d. potassium hypochlorite KClO₄

e. potassium iodide KI

2. Dissociation (ionization):

a. potassium oxide, K₂O

K₂O does not dissociate but react with water to product KOH, then KOH dissociates, but there is not such thing as a 0.300 M solution of K₂O.

b. potassium phosphate:

K₃PO₄ → 3K³⁺ + PO₄¹⁻ 3 K⁺¹ ions per unit formula

c. potassium hydrogen carbonate

KHPO₃ → K⁺¹ + HPO₃⁻¹ 1 K⁺¹ ion per unit formula

d. potassium hypochlorite

KClO₄ → K⁺¹ + HClO₄⁻¹ 1 K⁺¹ ion per unit formula

e. potassium iodide

KI → K⁺¹ + I⁻¹ 1 K⁺¹ ion per unit formula.

Hence, the 0.300 M solution of potasssium phosphate produces the highest concentration of potassium ions.

6 0

3 years ago

Consider the reaction for the decomposition of hydrogen disulfide: 2H2S(g)⇌2H2(g)+S2(g), Kc = 1.67×10−7 at 800∘C A 0.500 L react

trasher [3.6K]

Answer:

Molar concentration of S₂ is 1.77×10⁻⁶M

Explanation:

For the reaction:

2H₂S(g) ⇄ 2H₂(g) + S₂(g)

The equilibirum constant, K, is defined as:

$K = \frac{[S_2][H_2]^2}{[H_2S]^2}$ (1)

Concentrations in equilibirum are:

[H₂S] : 0,163/0.500L - X

[H₂] : 0,0500/0.500L + X

[S₂] : X

Replacing the concentrations and the equilibrium value in (1):

$K = \frac{[X][0.1+X]^2}{[0326-X]^2}$

1.67x10⁻⁷ = X (X² + 0.2X + 0.01) / (X² -0.652X + 0.106)

1.67x10⁻⁷X² - 1.09x10⁻⁷X + 1.77x10⁻⁸ = X³ + 0.2X² + 0.01X

0 = X³ + 0.2X² + 0.01X - 1.77x10⁻⁸

Solving for X:

X = 1.77×10⁻⁶

As [S₂] = X, molar concentration of S₂ is 1.77×10⁻⁶M

I hope it helps!

5 0

3 years ago