How many atoms are in 2.5 moles of beryllium atoms?

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

What shape would a molecule with two bound groups and two lone pairs have?

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