Use the table on the right to calculate each required quantity.

the quantity of heat required to melt 175.0 g cu: kj

the mass of a sample of nacl that requires 450.1 kj of heat to melt fully: g

the identity of a substance that releases 21.2 kj of energy when 1.42 mol freezes:

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.