Answer:
Reversible reactions exhibit the same reaction rate for forward and reverse reactions at equilibrium.
Reversible reactions exhibit constant concentrations of reactants and products at equilibrium
Explanation:
A reversible reaction is a reaction that can proceed in both forward and backward direction.
Equilibrium is attained in a chemical system when there is no observable change in the properties of the system.
At equilibrium, a reversible reaction is occurring in at same rate. That is, the forward and backward reaction is occurring at the same rate. As the rate of the forward and backward reaction remains the same, the concentrations of the reactants and products will also be the same in order for the equilibrium to be maintained.
Answer:
Refraction is the bending of a wave when it enters a medium where its speed is different, like going from the air (gas) to a glass of water (liquid). Absorption is when light energy penetrates an object. Typically this energy is then converted to heat.
Answer:
C) 4.
Explanation:
Hello!
In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:

We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.
Therefore, nickel has C) 4 different principal quantum numbers.
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