What pattern have you noticed between the number of valence electrons an element has and it’s placement on the periodic table?

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

The lattice enthalpy (formation of ionic solid from ions in the gas phase) for agcl(s) is -916 kj/mol and the hydration enthalpy (dissolution of gaseous ions into water) is -850 kj/mol. how much heat (in joules) is involved in forming 1l of saturated agcl solution (1.8 × 10-4 g / 100 ml water) by dissolving agcl(s)? assume solution volume does not change much upon dissolution. the equations are given below. ag+(g) + cl−(g) æ agcl(s)