Answer:
NH₃ (Option A)
Explanation:
Arrhenius theory explained that the acids are the ones that have H⁺, either H in its formula. Following this, the bases are the ones that have OH⁻ , either OH and its formula.
It can be used only with compounds with H, or OH.
So the ammonia is not a base, as Arrhenius theory.
It is known that ammonia behaves as a weak base, but it does not have hydroxide ions that can yield to water
Answer:

Explanation:
Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.
With Hess's Law in mind, let's see how A can be converted to 2C +E.
(Δ
) -----(1)
Since we have 2B, multiply the whole of II. by 2:
(2Δ
) -----(2)
This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is
.
Reversing III. gives us a negative enthalpy change as such:
(-Δ
) -----(3)
This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of
, which is also the equation of interest.
Adding all three together:
(
)
Thus, the first option is the correct answer.
Supplementary:
To learn more about Hess's Law, do check out: brainly.com/question/26491956
Answer:
A is the correct answer.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example in case of Helium:
The 1st one diagram shows that arrow is pointing with in nucleus. The helium nucleus contain two protons and two neutrons. Thus maximum mass is present with in nucleus. while two electrons are revolve around the nucleus and mass of electron is negligible.
A dichotomous key is an important scientific tool, used to identify different organisms, based the organism's observable traits. Dichotomous keys consist of a series of statements with two choices in each step that will lead users to the correct identification.