An atom in the ground state has two electrons in its first shell and six electrons in its second shell. what is the total number of protons in the nucleus of this atom? (1) 5 (2) 2 (3) 7 (4) 8

What amount of heat is exchanged when 106.2 grams of substance y goes from a liquid at 35 degrees celsius to a solid at the same temperature? melting point of substance y = 35 degrees c; δhvaporization = 3.67 j/mol; δhfusion = 3.30 j/mol. mwsubstance y = 28.22 g/mol. −12.4 j −3.51 x 102 j 1.24 x 101 j 351 j