Does 3Na2SO4 have any chlorine atoms ?

The enthalpy of formation of water is -285.8 kj/mol. what can be inferred from this statement?

If two atoms are bonded to a central atom with no lone pairs,how will they be arranged

Astream of surface water reaches a porous portion of sediment and seeps into the ground. this water eventually joins a large reservoir of water located beneath the earth's surface. the example above describes the interacting with the a. cryosphere; biosphere b. hydrosphere; biosphere c. hydrosphere; geosphere d. cryosphere; geosphere