Each element absorbs light at specific wavelengths unique to that atom. When astronomers look at an object's spectrum, they can determine its composition based on these wavelengths. The most common method astronomers use to determine the composition of stars, planets, and other objects is spectroscopy.
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<h2>Answer:</h2>
Arrangement of inter molecular forces from strongest to weakest.
- Hydrogen bonding
- Dipole-dipole interactions
- London dispersion forces.
<h3>Explanation:</h3>
Intermolecular forces are defined as the attractive forces between two molecules due to some polar sides of molecules. They can be between nonpolar molecules.
Hydrogen bonding is a type of dipole dipole interaction between the positive charge hydrogen ion and the slightly negative pole of a molecule. For example H---O bonding between water molecules.
Dipole dipole interactions are also attractive interactions between the slightly positive head of one molecule and the negative pole of other molecules.
But they are weaker than hydrogen bonding.
London dispersion forces are temporary interactions caused due to electronic dispersion in atoms of two molecules placed together. They are usually in nonpolar molecules like F2, I2. they are weakest interactions.
<u>Answer:</u> The correct answer is Option b.
<u>Explanation:</u>
Reducing agents are defined as the agents which help the other substance to get reduced and itself gets oxidized. They undergo oxidation reaction.

For determination of reducing agents, we will look at the oxidation potentials of the substance. Oxidation potentials can be determined by reversing the standard reduction potentials.
For the given options:
- <u>Option a:</u>

This ion cannot be further oxidized because +1 is the most stable oxidation state of silver.
- <u>Option b:</u>

This metal can easily get oxidized to
ion and the standard oxidation potential for this is 0.13 V

- <u>Option c:</u>

This metal can easily get oxidized to
ion and the standard oxidation potential for this is 0.0 V

- <u>Option d:</u>

This metal can easily get oxidized to
ion and the standard oxidation potential for this is -0.80 V

- <u>Option e:</u>

This ion cannot be further oxidized because +2 is the most stable oxidation state of magnesium.
By looking at the standard oxidation potential of the substances, the substance having highest positive
potential will always get oxidized and will undergo oxidation reaction. Thus, considered as strong reducing agent.
From the above values, the correct answer is Option b.
Only the Fe is unbalanced.
:)
Answer is: ph value of pyridine solution is 9.1.
Chemical
reaction: C₅H₅N +
H₂O → C₅H₅NH⁺ + OH⁻.<span>
c(pyridine - C</span>₅H₅N)
= 0.115M.<span>
Kb(C</span>₅H₅N)
= 1.4·10⁻⁹.
[C₅H₅NH⁺] = [OH⁻] = x; equilibrium concentration.<span>
[</span>C₅H₅N] =
0.115 M - x.
Kb = [C₅H₅NH⁺] · [OH⁻] / [C₅H₅N].
1.4·10⁻⁹ = x² / (0.115 M -x)
Solve quadratic equation: x = [OH⁻] = 0.0000127 M.<span>
pOH = -log(0.0000127 M) = 4.9</span>
<span>pH = 14 - 4.9 = 9.1.</span>