What do these two changes have in common? Erosion caused by wind
Snowflakes forming in a cloud
Both are only physical change
Both are chemical change
Both are caused by heating
Both are caused by cooling

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.