What happens when an electron moves from a high energy level to a lower one?
a. it absorbs light
b. it emits light
c. it disappears
d. it gets bigger

Which substances have the lowest melting points: ionic covalent, or metallic

1. combine iron and copper (ii) sulfate solution. (hint: iron will form the iron (iii) ion) fe + cuso4 → 2. combine lead (ii) nitrate and potassium iodide solutions. pb(no3)2+ kl → 3. combine magnesium metal and hydrochloric acid solution. mg + hcl → 4. electrolysis (splitting) of water. h2o → 5. burning magnesium. mg + o2 →

Which characteristics can be used to differentiate star systems? check all that apply.