Answer: Protons
WHY?
Changing electrons will only result in the same element having different charges and hence, changing it's chemical properties.
Changing neutrons will not change an element but it will result in an isotope forming instead. (Isotopes are elements of the same type with different neutron numbers.)
However, changing the proton number would immediately change the nucleus composition, resulting in a change in element with a negative charge as there are more electrons than protons. This results in a expansion in valance electrons's distance from the nucleus. This results in a change in chemical properties of the element.
Therefore, a change in Protons is the answer.
Answer:
A i. Internal energy ΔU = -4.3 J ii. Internal energy ΔU = -6.0 J B. The second system is lower in energy.
Explanation:
A. We know that the internal energy,ΔU = q + w where q = quantity of heat and w = work done on system.
1. In the above q = -7.9 J (the negative indicating heat loss by the system). w = 3.6 J (It is positive because work is done on the system). So, the internal energy for this system is ΔU₁ = q + w = -7.9J + 3.6J = -4.3 J
ii. From the question q = +1.5 J (the positive indicating heat into the system). w = -7.5 J (It is negative because work is done by the system). So, the internal energy for this system is ΔU₂ = q + w = +1.5J + (-7.5J) = +1.5J - 7.5J = - 6.0J
B. We know that ΔU = U₂ - U₁ where U₁ and U₂ are the initial and final internal energies of the system. Since for the systems above, the initial internal energies U₁ are the same, then we say U₁ = U. Let U₁ and U₂ now represent the final energies of both systems in A i and A ii above. So, we write ΔU₁ = U₁ - U and ΔU₂ = U₂ - U where ΔU₁ and ΔU₂ are the internal energy changes in A i and A ii respectively. Now from ΔU₁ = U₁ - U, U₁ = ΔU₁ + U and U₂ = ΔU₂ + U. Subtracting both equations U₁ - U₂ = ΔU₁ - ΔU₂
= -4.3J -(-6.0 J)= 1.7 J. Since U₁ - U₂ > 0 , U₂ < U₁ , so the second system's internal energy increase less and is lower in energy and is more stable.
Answer:
No
Explanation:
The chemical reaction between magnesium metal and hydrochloric acid solution is not an acid - base reaction.
An acid - base reaction involves an acid and base to produce salt and water.
- This reaction is called a neutralization reaction.
- An acid is a substance that produces excess hydroxonium ions in solutions.
- A base produces excess hydroxyl ions in solution.
- When acids and base combines, the main product is a salt in water solution.
