3. Why does å star begin shining?

Chemistry

2 answers:

steposvetlana [31]2 years ago

8 0

Answer:

a star shines due to thermonuclear fusion

Explanation:

Nimfa-mama [501]2 years ago

8 0

Answer:

If heated and intense enough nuclear fusion is in the center of the star will continue. It takes a star the size of our sun about 20 million years to reach this point. Once it starts nuclear fusion, the star can shine for about 10 billion years.

Explanation:

You might be interested in

The boiling point of water is 100.0°C at 1 atmosphere. How many grams of sodium acetate (82.04 g/mol), must be dissolved in 283.

Alecsey [184]

Answer:

I have to weight 10,04 g of acetate sodium

Explanation:

This is the colligative propertie about elevation of boiling point

ΔT = Kb . m . i

ΔT is the difference between T° at boiling point of the solution - T° at boiling point of the solvent pure - we have this data 0,450°C

Kb means ebulloscopic constant (0,52 °C.kg/m .- a known value for water)

m means molality (moles of solute in 1kg of solvent)

i means theVan 't Hoff factor (degree of dissociation for a compound)

For the sodium acetate is 2

NaCH3COO ---> Na+ + CH3COO-

0,450°C = 0,52°C.kg/m . m . 2

0,450°C / (0,52°C.kg/m . 2) = m

0,432 m/kg = m

This number means I have 0,432 moles of acetate sodium, my solute in 1kg of water, my solvent. But I don't have 1000 g (1kg) I only have 283 g so let's make the rule of three:

1000 g _____ 0,432 moles

283 g ______ (283g .0,432m) / 1000g = 0,122 moles

Now that I have the moles of acetate sodium, I have to find the mass.

Moles . molar mass = mass

0,122 moles . 82.04 g/mol = 10,04 g

3 0

3 years ago

Read 2 more answers

Zinc sulfate is a 2-ion electrolyte,

Gekata [30.6K]

Answer: The value of i is 1.4 and 40% dissociation of 100 particles of zinc sulfate will yield 60 undissociated particles.

Explanation: