Sort the following into the classification for a reaction that is NOT at equilibrium versus a reaction system that has reached equilibrium. Drag the appropriate items to their respective bins.
The rate at which products form from reactants is equal to the rate at which reactants form from products.
The concentrations of reactants and products are stable and cease to change.
The concentration of products is increasing, and the concentration of reactants is decreasing.
The ratio of products to reactants is not stable.
The ratio of products to reactants does not change.
Chemical equilibrium is a dynamic state.
The rate of the forward reaction is greater than the rate of the reverse reaction.
The state of chemical equilibrium will remain the same unless reactants or products escape or are introduced into the system. This will disturb the equilibrium.
The forward and reverse reactions proceed at the same rate.
The products are gaseous and escape the vessel into the atmosphere.
The reaction has reached equilibrium.
The reaction has not reached equilibrium.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.

fe 55.85 g/mol and h2o 18.02 g/mol.

1 is the answer to this problem