12. The pure substance that cannot be broken down into simpler ones are called A.compounds
B. elements
C. mixtures
D. solutions

13. Which of the following is a physical property of an element?
A. color
B. flammability
C. stability
D. toxicity

14. Which of the following is a chemical property of an element?
A. acidity
B.mass
C.shape
D.volume

15. Which of the following substances is an element?
A.candle wax
B.cookies
C. cooking oil
D. Copper

16. What are elements made of?
Aatoms
B. compounds
C. dust particles
D.gases

17.Which characterizes a luster property of an element?
A. resistant
B. poisonous
C. easily burnt
D. shiny appeara

18.Which property of an element refers to the amount of space it may occupy?
A. color
B. oxidation
C. shape
D. volume

19. Which can be considered as a form of matter?
C. light
D. shadow
A.energy
B. ice

20.What compose an element?
Amany molecules
B.Neutron
C.one kind of atoms
D. Proton​