*identify if the following are physical (p) or chemical (c) characteristics: 1) __ sodium (na) is a very reactive alkali metal. 2) __ oxygen (o) is a gas. 3) __ wood is flammable. 4) __ a ruby is red. 5) __ copper (cu) conducts electricity. 6) __ water (h2o) freezes at 0 degrees celsius. 7) __ iron (fe) reacts with water to form rust. 8) __ silver (ag) reacts with moisture in the air to form tarnish. 9) __ the chalkboard is magnetic. 10) __ sand and dirt are mixed in a flower pot.