Answer:
the first one which is A
Explanation:
the burning of fossil fuels causes both air pollution and water pollution
Answer:
Melting: the substance changes back from the solid to the liquid. Condensation: the substance changes from a gas to a liquid. Vaporization: the substance changes from a liquid to a gas. Sublimation: the substance changes directly from a solid to a gas without going through the liquid phase.
Explanation:
Answer:
1. A state of balance in which the rates of the forward and reverse reactions are equal.
Explanation:
A dynamic equilibrium is like a cycle, the reactants change to products, but the products also change to reactants keeping the amount of each constant.
2. A state of balance in which the forward reaction stops but reverse reaction continues.
In this statement there isnt a equilibrium. The products will change to reactants until the reaction stops.
3. A state of balance in which the forward reaction continues but reverse reaction stops.
Here the reactants will change to products until the reaction stops.
4. A state of balance in which the forward and reverse reactions stop.
In this case the reaction has stopped.
Answer:

Explanation:
To answer this question successfully, we need to remember that atoms are neutral species, since the number of protons, the positively charged particles, is equal to the number of electrons, the negatively charged particles. That said, we may firstly find an atom which has 3 electrons (and, as a result, 3 protons, as it should be neutral).
The number of protons is equal to the atomic number of an element. We firstly may have an atom with 3 protons and 3 electrons (atomic number of 3, this is Li).
Similarly, we may take the atomic number of 4, beryllium, and remove 1 electron from it. Upon removing an electron, it would become beryllium cation,
.
We may use the same logic going forward and taking the atomic number of 5. This is boron. In this case, we need to remove 2 electrons to have a total of 3 electrons. Removal of 2 electrons would yield a +2-charged cation:
.