What is the prefix for the number of atoms of an element when there are four atoms of that element in the compound?

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

Kc = 0.040 for the system below at 450oc. if a reaction is initiated with 0.40 mole of cl2 and 0.40 mole of pcl3 in a 2.0 liter container, what is the equilibrium concentration of cl2 in the same system? pcl5(g) ⇄ pcl3(g) + cl2(g)

Covalent compounds: mastery test select the correct answer what is formed when atoms join together with a covalent bond? a. an ion b. a molecule c. a neutral atom d. a noble gas