Please help me with this please please

When will le chatelier's principle come into effect? at the beginning of a reaction, when there are only reactants when a reaction has reached chemical equilibrium when a catalyst is added to a reaction mixture when a reaction is occurring but not yet at equilibrium

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

Which rate indicates the number of children that would be born per woman if she were to live to the end of her child bearing years