Answers to the unit review on Elementary my dear Watson


1. atom  2.carbon  3. chemical  4.conservation  5. electrons  6. element  7. mass  8.matter  9.molecule              10. number  11. protons  12. period  13. physical

Unit Review

1.atoms  2. negative, positive, no (or neutral)  3. 1      4. families,   periods    

5.  - atomic number

      - chemical symbol

      - chemical name

      - atomic mass

6. chemical symbol Cl      number of protons 17

atomic number   17          number of electrons 17

atomic mass 35 amu     number of neutrons 18  (not on the test)

7. compounds MUST have all different atoms like H2O.... all the atoms are different. A molecule can be simple, contain the same atoms ex: O3

8. Na: sodium (1 atom)    H: hydrogen (1 atom)    C: carbon (1 atom)   O: oxygen (3 atoms)

9. draw 2 white circles attached to 2 red circles

10. chemical change: the substances reacting are changing nature and are not reversible.

physical change: the substances are NOT changing nature and reversible (only in a change of state)

11. production of a gas, production of heat, production of light, change of color, production of a solid

12. chemical change: there's a change of color, and it is not reversible... also a new substance is created (burned toast)

13. They are made of different liquids. Different liquids means different atoms.Which means different masses.