Describe how the calcium atom and the oxygen atom forms calcium oxide. You should give the charge on each ion formed.

List four observations that indicate that a chemical reaction may be taking place

Acrystal that absorvd water from air is (blank)a. aqueousb. homogenousc. hygroscopicd. efflorescent

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6