The graph shows temperature versus time for 1.0 kilogram of a substance at constant pressure as heat is added at a constant rate of 100 kilojoules per minute The substance is solid at 20° C.
100 110 120 130
Time (min.)
How much heat was added to change the substance from a liquid at its melting point to a vapor at its boiling point?
3000 kJ
6000 kJ
9000 kJ
11000 kJ
2
3
4
Såbmit Answer

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.

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.