I have 8 valence electrons, completely nonreactive, and my family contains Helium that is used to fill balloons! I must be a... a
metal
b
nonmetal
c
metalloid
d
noble gas

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.