Grade 10 Physical Sciences chemistry quiz

Which ONE of the following is a good conductor of electricity?

• Wood

• Plastic

• Silicon

• Copper

Refer to the table below to fill in the spaces in the following sentence. The density of the metals ... and that of non-metals ... across period 2 of the periodic table.

• Decreases Increases

• Decreases Decreases

• Increases Decreases

• Increases Increases

Which ONE of the following molecular mass represents hydrogen chloride?

• 57,5

• 35,5

• 36,5

• 40,2

The bonding between crystal lattices can only be a/an ... bond.

• ionic

• metallic

• covalent

• pure

Study the diagram below. The diagram above represents the following:

• A lattice structure between ions

• A buckminsterfullerene of sulphur

• Intermolecular forces between molecules

• Positive metal kernels and the sea of delocalised electrons

Thando slowly heats a chocolate bar and observes the changes. Which ONE of the following is the most accurate conclusion?

• Chocolate undergoes a chemical change

• Chocolate undergoes a physical change

• Chocolate decomposes into its constituent components

• Chocolate undergoes no change

Study the equation below: 2H2(g) + O2(g) → 2H2O(g) Which ONE of the statements below is CORRECT?

• 2 molecules of hydrogen gas react with 1 atom of oxygen gas to form 2 atoms of water vapour.

• 2 moles of hydrogen gas react with 1 mole of oxygen gas to form 2 moles of water vapour

• 4 atoms of hydrogen gas react with 2 molecules of oxygen gas to form 2 moles of water vapour.

• 4 g of hydrogen gas react with 16 g of oxygen gas to form 18 g of water vapour.

An aqueous mixture in a test tube contains Ag+(aq), K+(aq) and Pb+(aq). How many different solids will form when NaCℓ(aq) is added to this mixture?

• None

• 1

• 2

• 3

SO2 gas dissolves in water and contributes to acid rain. What is the name of the acid that forms during this reaction?

• Sulfuric acid

• Carbon dioxide acid

• H2CO3

• Carbonic acid

Define the term element.