All categories

3 years ago

What occurs during the death of a large star to make all heavy elements?

1 answer:

7 0

As the star collapses, fusion occurs in the core of the star. This process compacts atoms and if the star is sufficiently massive, stellar nucleosynthesis takes place and heavier elements are formed. If nuclear fusion is unable to prevent gravitational collapse, the star will blow itself apart as a supernova, ejecting the heavier elements into space at very high speed. So space is seeded with heavier elements, to be captured by the gravitational attraction of other celestial bodies and absorbed into solar systems.

You might be interested in

What determines what elements end up on the periodic table?

AfilCa [17]

Their atomic number

7 0

3 years ago

Sterling silver contains silver and copper metals. if a sterling silver chain contains 17.6g of silver and 2.40g of copper, what

Bogdan [553]

Answer:- 0.88

Solution:- Masses of silver and copper metals are given and we are asked to calculate the percentage of silver in the alloy.

mass percent of Ag = $(\frac{mass of Ag}{mass of alloy})*100$

Mass of Ag = 17.6 g

mass of Cu = 2.40 g

mass of alloy = 17.6 g + 2.40 g = 20.0 g

Let's plug in the values in the formula:

mass percentage of Ag = $(\frac{17.6}{20.0})*100$

mass percentage of Ag = 88%

So, the mass percentage of silver in sterling silver is 88% and in decimal form it is 0.88.

7 0

3 years ago

O 1. 12 moles

mars1129 [50]

Answer:

$n_{H_2O}=5.94molH_2O$

Explanation:

Hello there!

In this case, according to the given question about stoichiometry, it is possible for us to calculate the required moles of water that will be produced by 12 grams of hydrogen, by using the molar mass of this reactant (2.02 g/mol as it is diatomic) and the 2:2 mole ratio in the chemical equation by solving the following setup:

$n_{H_2O}=12gH_2*\frac{1molH_2}{2.02gH_2} *\frac{2molH_2O}{2molH_2} \\\\n_{H_2O}=5.94molH_2O$

Regards!

3 0

2 years ago

Using the Rydberg formula, calculate the initial energy level when an electron in a hydrogen atom transitions into n= 2 and emit

EleoNora [17]

Answer:

Explanation:

Using the Rydberg formula as:

$\frac {1}{\lambda}=R_H\times Z^2\times (\frac {1}{n_{1}^2}-\frac {1}{n_{2}^2})$

where,

λ is wavelength of photon

R = Rydberg's constant (1.097 × 10⁷ m⁻¹)

Z = atomic number of atom

n₁ is the initial final level and n₂ is the final energy level

For Hydrogen atom, Z= 1

n₂ = 2

Wavelength = 410.1 nm

Also,

1 nm = 10⁻⁹ m

So,

Wavelength = 410.1 × 10⁻⁹ m

Applying in the formula as:

$\frac {1}{410.1\times 10^{-9}}=1.097\times 10^7\times 1^2\times (\frac {1}{n_{1}^2}-\frac {1}{2^2})$

Solving for n₁ , we get

n₁ ≅ 1

3 0

3 years ago

Read 2 more answers

(06.01 MC)

skelet666 [1.2K]

Answer:

Part 1. When the balloon is filled half of the way, and placed into the freezer, it will shrink. This happens because kinetic molecular theory tells us that a decrease in temperature decreases the kinetic energy of the gas molecules in the balloon. Viscous gases like hydrogen are less likely to shrink.

Part 2. When the balloon is placed out in the hot sun, most likely the balloon will swell and grow. This happens because the kinetic energy of the gas molecules increases due to solar radiation transforming into heat energy and then transforming into kinetic energy. Sticky gases like neon are more likely to grow.

Explanation:

7 0

3 years ago