Can someone help me with this please?

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

Which are forms of frozen water? check all that apply. dew frost hail rain sleet

Which best describes the activation energy of a chemical reaction? a. the combined energy of all the reactants b. the amount of energy required for a reaction to occur c. the difference in energy between products and reactants d. the potential energy stored in the bonds of reactants and products