An example can be perspiration or even rain.
Hope this helps.
It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms.
These were mainly helium and hydrogen, which are still by far the most abundant elements in the universe. Present observations suggest that the first stars formed from clouds of gas around 150–200 million years after the Big Bang. Heavier atoms such as carbon, oxygen and iron, have since been continuously produced in the hearts of stars and catapulted throughout the universe in spectacular stellar explosions called supernovae.
Answer:
<h3>1)</h3>
Structure One:
Structure Two:
Structure Three:
Structure Number Two would likely be the most stable structure.
<h3>2)</h3>
- All five C atoms: 0
- All six H atoms to C: 0
- N atom: +1.
The N atom is the one that is "likely" to be attracted to an anion. See explanation.
Explanation:
When calculating the formal charge for an atom, the assumption is that electrons in a chemical bond are shared equally between the two bonding atoms. The formula for the formal charge of an atom can be written as:
.
For example, for the N atom in structure one of the first question,
- N is in IUPAC group 15. There are 15 - 10 = 5 valence electrons on N.
- This N atom is connected to only 1 chemical bond.
- There are three pairs, or 6 electrons that aren't in a chemical bond.
The formal charge of this N atom will be
.
Apply this rule to the other atoms. Note that a double bond counts as two bonds while a triple bond counts as three.
<h3>1)</h3>
Structure One:
Structure Two:
Structure Three:
In general, the formal charge on all atoms in a molecule or an ion shall be as close to zero as possible. That rules out Structure number one.
Additionally, if there is a negative charge on one of the atoms, that atom shall preferably be the most electronegative one in the entire molecule. O is more electronegative than N. Structure two will likely be favored over structure three.
<h3>2)</h3>
Similarly,
- All five C atoms: 0
- All six H atoms to C: 0
- N atom: +1.
Assuming that electrons in a chemical bond are shared equally (which is likely not the case,) the nitrogen atom in this molecule will carry a positive charge. By that assumption, it would attract an anion.
Note that in reality this assumption seldom holds. In this ion, the N-H bond is highly polarized such that the partial positive charge is mostly located on the H atom bonded to the N atom. This example shows how the formal charge assumption might give misleading information. However, for the sake of this particular problem, the N atom is the one that is "likely" to be attracted to an anion.
A buffer solution contains an equivalent amount of acid and base. The pH of the solution with an acid dissociation constant (pKa) value of 3.75 is 3.82.
<h3>What is pH?</h3>
The amount of hydrogen or the proton ion in the solution is expressed by the pH. It is given by the sum of pKa and the log of the concentration of acid and bases.
Given,
Concentration of salt [HCOO⁻] = 0.24 M
Concentration of acid [HCOOH] = 0.20 M
The acid dissociation constant (pKa) = 3.75
pH is calculated from the Hendersons equation as,
pH = pKa + log [salt] ÷ [acid]
pH = 3.75 + log [0.24] ÷ [0.20]
= 3.75 + log (1.2)
= 3.75 + 0.079
= 3.82
Therefore, 3.82 is the pH of the buffer.
Learn more about pH here:
brainly.com/question/27181245
#SPJ4