5. An element contains only one kind of

A. protein
B. property
C. atom
D. raw material

6. When two or more different elements join together chemically,

A. the physical properties of the substances remain the same.
B. a mixture is formed
C. a substance that is the same as the elements is formed.
D. a compound is formed

7. Carbon is considered an element, while carbon dioxide is considered a compound. This is because carbon dioxide is

A. a gas at room temperature
B. made up of two different elements
C. given off by animals.
D. separated by physical means

8. O is the symbol for oxygen, while H is a symbol for

A. helium
B. hafnium
C. hassium
D. hydrogen

9. Which of these is the correct symbol for aluminum?

Α. ΑΙ
B. aL
C. AL
D. A

10. Elements play an important role in the human body. Which of the following is correct?

A. Aluminum is an essential mineral for bones and teeth.
B. Oxygen is a gas needed for breathing C. Sodium is used as a sweetener
D. Iron is necessary for healthy hair and skin

11. Table sugar is also called sucrose, while table salt is a
A. sodium carbonate
B. sodium chloride
C. sodium carbonara
D. calcium carbide

12. What kind of a pure substance is sodium chloride?

A. element
B. mixture
C. alloy
D. compound

13. Which of the following is a pure substance?

A. lemon juice drinks
B. gold
C. halo-halo
D. pinakbet

14. The symbol of an element starts with a

A. capital letter
B. small letter
C. number
D. exponent

15 Which of these is the correct chemical formula for water?

A. HO2
B. H3O
C. H2O
D. HO3​