Wht is a atom and a nucleus

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

What does a particular point on a line of a phase diagram represent? o a. the maximum temperature a substance can exist at without bonds breaking b. the pressure created by the kinetic energy of molecules at a particular temperature c. the melting point or boiling point of a substance at a specific pressure d. the conditions in which temperature and pressure have equal effects on a substance

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same