What force holds electrons in atoms

1. Which is an example of covalent bonding?

iren [92.7K]

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sin theta equals to cos theta then the value of sin 2 theta

8 0

3 years ago

A solution of nitrous acid and potassium nitrite acts as a buffer due to reactions that occur within the solution when a strong

Ghella [55]

Answer:

a. NO₂⁻ + H⁺ → HNO₂

b. HNO₂ + OH⁻ → NO₂⁻ + H₂O

Explanation:

A buffer is defined as an aqueous mixture of a weak acid and its conjugate base or vice versa.

The buffer of the problem is HNO₂/NO₂⁻ <em>where nitrous acid is the weak acid and NO₂⁻ is its conjugate base.</em>

a. When a acid is added to a buffer as the buffer of the problem, the conjugate base will react with the acid, to produce the weak acid, thus:

NO₂⁻ + HCl → HNO₂ + Cl⁻

Ionic equation is:

NO₂⁻ + H⁺ + Cl⁻ → HNO₂ + Cl⁻

In the net ionic equation, you avoid the ions that don't react, that is:

b. In the same way, the weak acid will react with the strong acid producing water and the conjugate base, thus:

HNO₂ + NaOH → NO₂⁻ + H₂O + Na⁺

The ionic equation is:

HNO₂ + Na⁺ + OH⁻ → NO₂⁻ + H₂O + Na⁺

And the net ionic equation is:

5 0

3 years ago

All of the statements regarding the symbol "ΔH" are correct except it

trapecia [35]

Answer: Option (D) is the correct answer.

Explanation:

Enthalpy is defined as the amount of energy needed or removed from a substance. It is represented by $\Delta H$ .

Basically, it is the change in enthalpy and it represents the difference between the energy used in breaking bonds and the energy released in formation of bonds in a chemical reaction.

It is also known as heat of reaction. When value of $\Delta H$ is positive then it means heat is absorbed in the chemical reaction.

When value of $\Delta H$ is negative then it means that heat is released in the chemical reaction.

Whereas entropy means the measure of randomness. It is represented by $\Delta S$ . We cannot calculate entropy but we can measure the change in entropy.

Thus, we can conclude that all of the statements regarding the symbol "ΔH" are correct except it that can be called entropy change.

6 0

3 years ago

Which of these gives a correct trend in ionization energy

natita [175]

Answer:

C. I, III , IV

Explanation:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.

3 0

3 years ago

Which type of bond stores the most energy

Ronch [10]

Answer:

I'm not sure which bond stores the most energy but the ionic bond is stronger than the covalent bond.

Explanation:

7 0

3 years ago