All categories

3 years ago

How did the elements begin to stratify?

Chemistry

1 answer:

Bogdan [553]3 years ago

8 0

Answer:

The process of elemental stratification relies on the diffusion velocity, which causes the migration of the different chemical elements within stars.

Explanation:

You might be interested in

When did the water level in Lake Mead become a concern?

xenn [34]

Answer:

in 1983, Lake Mead had a recorded water level of 1,225 feet above sea level. The closest it's been to that level in modern times was in 2000. Explanation:

6 0

2 years ago

How is particle motion related to thermal equilibrium?

Wewaii [24]

Answer:

With billions of moving particles colliding into each other, an area of high energy will slowly transfer across the material until thermal equilibrium is reached (the temperature is the same across the material).

8 0

3 years ago

Where is the majority of Earth’s water found? glaciers

galben [10]

Oceans are the most common of course

5 0

3 years ago

Calculate the molarity of 0.850 mol of Na2S in 1.70 L of solution.

Basile [38]

Molarity is simply the ratio of the number of moles of a substance over the total volume of the solution. Assuming that the addition of 0.850 moles does not change the overall volume of 1.70 L, therefore molarity is simply:

Molarity = 0.850 moles / 1.70 L = 0.5 moles / L = 0.5 M

5 0

3 years ago

Effective nuclear charge, Zeff, is defined as:

Alborosie

Answer:

The effective nuclear charge for a valence electron in oxygen atom: $Z_{eff} = 4.55$

Explanation:

Effective nuclear charge $[Z_{eff}]$ is the net nuclear charge experienced by the electron in a given atom. It is always less than the actual charge of the nucleus [Z], due to shielding by electrons in the inner shells.

It is equal to the difference between the actual nuclear charge or the atomic number (Z) and the shielding constant (s).

$\Rightarrow Z_{eff} = Z - s$

For an oxygen atom-

Electron configuration: (1s²) (2s² 2p⁴)

The atomic number (actual nuclear charge): Z = 8

The shielding constant (s) for a valence electron can be calculated by using the Slater's rules:

⇒ s = 5 × 0.35 + 2 × 0.85 = 1.75 + 1.7 = 3.45

Therefore, the effective nuclear charge for a valence electron in oxygen atom is:

$Z_{eff} = Z - s = 8 - 3.45 = 4.55$

Therefore, the effective nuclear charge for a valence electron in oxygen atom: $Z_{eff} = 4.55$

6 0

3 years ago