Potential energy diagram for the reaction
2H,0 + 572 kJ → 2H2 +0,
| H₂O₂
Potential Energy
H2O
Time
A. exothermic
B. endothermic

"the periodic table is arranged in order of atomic number."

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.

po-215 i got it right on the quiz