Consider the total ionic equation below.
2NH3 +20H-+ 2H++502- 2NH3 + 2H2O+502-
What are the spectator ions in this equation?
O H+ and OH-
O H* and NHI
O NHI and 503
O 502 and OH-

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

i just learnt this recently but i need to look through my notes again

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?