I think that the answer is A because if you think about water for an example. When water turns into ice, it's still technically water, just the molecules are frozen. The water is physically changed. It could also see why you think it is B but I don't think so completely. It doesn't really make sense to me. So I'd choose A. It's definitely not C or D.
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
Answer:
D
Explanation:
The high jump of ionization energy indicates that we are trying to remove electron from noble gas configuration state.
The ionization energy data specifies that the Elements are from group 1 at period 3 or greater.
Removing the first electron require 496 kJ and the second ionization energy jump significantly due to the removal of electron from the noble gas configuration which is logical because electron try to maintain the especially stable state.
Answer:
<span>The energy required to go from liquid to gas is called as Latent Heat of Vaporization.
Explanation:
The process of conversion of liquid into gas phase is known as vaporization while the conversion of gas into liquid state is called as condensation. The liquid having stronger intermolecular forces than gases require some energy to break those interactions hence, the heat provided to break these interactions and convert it into gas phase is called as heat of vaporization. Remember, heat of vaporization and heat of condensation are same for a given substance but with different signs.
Example:
Heat of Vaporization of Water = 40.65 kJ/mol
Heat of Condensation of Water = - 40.65 Kj/mol</span>
Answer:
The last option:
- NH₃ (aq) + H⁺ (aq) → NH₄⁺ (aq)
Explanation:
1) Word equation
- Aqueous ammonia + nitric acid → aqueous ammonium nitrate
2) Chemical (molecular) equation
- NH₃ (aq) + HNO₃ (aq) → NH₄ NO₃
3) Ionization reactions
Write the dissociation of the soluble ionic compounds:
4) Total ionic equation:
- NH₃ (aq) + H⁺ (aq) + NO₃⁻ (aq) → NH₄⁺ (aq) + NO₃⁻ (aq)
5) Net ionic equation
You must cancel the spectator ions, which are those ions that are repeated in both reactant and product sides, i.e. NO₃⁻. They are name spectator because they do not participate (change) during the reaction.
- NH₃ (aq) + H⁺ (aq) → NH₄⁺ (aq)
And that is the last choice of the list.
