ICSE Class 6 Chemistry - Elements, Compounds and Symbols - Test 3 (Advanced)
1. A student writes Co instead of C for carbon. Why is this wrong?
A. Carbon has no symbol
B. Co represents another element
C. Symbols cannot have letters
2. Which statement shows the formation of a compound?
A. Sand and stones are mixed
B. Sugar is stirred in water
C. Elements combine chemically
3. Why is oxygen called an element?
A. It contains only one kind of atom
B. It is always mixed with water
C. It is made of many compounds
4. Which symbol is written correctly?
A. cL
B. Cl
C. CL
5. Why is water not called an element?
A. It has no mass
B. It is always a gas
C. It contains two elements chemically combined
6. A gold ornament may be represented by which symbol?
A. Au
B. Go
C. Gd
7. Which is the main difference between a compound and a mixture?
A. A compound is always visible
B. A compound is chemically formed
C. A mixture has only one element
8. Common salt contains sodium and chlorine chemically combined. It is therefore a:
A. Metal only
B. Mixture only
C. Compound
9. A nail is made mostly of iron. Which symbol represents iron?
A. Fe
B. In
C. Ir
10. What does a chemical formula usually represent?
A. Only the colour of a substance
B. A compound or molecule
C. Only a laboratory tool
11. Why should H and Hg not be confused?
A. Both mean hydrogen
B. Both mean mercury
C. They represent different elements
12. A pure copper wire is best described as:
A. An element
B. A compound
C. A sugar solution
13. Carbon dioxide can put out fire, but oxygen supports burning. This shows that a compound:
A. Has exactly the same properties as its elements
B. May have different properties from its elements
C. Is always a metal
14. Which symbol correctly represents potassium?
A. Po
B. Pt
C. K
15. Why do chemists use symbols for elements?
A. To write element names shortly
B. To hide the names of elements
C. To change elements into mixtures
16. Why is CA not the correct symbol for calcium?
A. Calcium has no symbol
B. The second letter should be small
C. Both letters must be small
17. Which description best fits a compound?
A. A substance with only one kind of atom
B. A substance made by simple mixing only
C. A substance made of elements chemically joined
18. Which pair is correctly matched?
A. Silver - Ag
B. Silver - S
C. Silver - Si
19. Which comes together chemically to form compounds?
A. Shadows
B. Elements
C. Sounds
20. Why must each element have its own proper symbol?
A. To make all elements look the same
B. To avoid writing science words
C. To identify elements clearly