The half-life of a sample of lawrencium Lr-262 is about 4 hours. How many hours must pass for only 25 grams of a 400-gram sample to remain

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

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

Which electron configuration represents the electrons in an atom of sodium in the ground state at stp