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Back in the lab, John tries dropping a piece of zinc into copper(II) sulfate solution. Which observation and explanation is correct?

Blue color darkens as more copper ions form. Hydrogen gas evolves as zinc reacts with water in the solution. No reaction occurs because zinc is less reactive than copper. Zinc dissolves and brown copper forms because zinc is more reactive than copper.

To test reactivity, Xinyi heats zinc oxide with carbon powder in a test tube. Which statement explains the result?

Carbon and zinc oxide react to produce carbon monoxide and zinc ions in solution. Carbon reduces zinc oxide to zinc because carbon is more reactive than zinc. Zinc oxide oxidizes carbon to zinc carbonate. Zinc remains as oxide because zinc is more reactive than carbon.

Xinyi challenges John to predict which carbonate decomposes most easily upon heating. Given: calcium carbonate, zinc carbonate, copper(II) carbonate, and silver carbonate. Which is the correct order from most stable to least stable?

Calcium carbonate > Zinc carbonate > Copper(II) carbonate > Silver carbonate Silver carbonate > Copper(II) carbonate > Zinc carbonate > Calcium carbonate Silver carbonate > Zinc carbonate > Copper(II) carbonate > Calcium carbonate Zinc carbonate > Calcium carbonate > Silver carbonate > Copper(II) carbonate

During a school experiment, John burns magnesium in steam to show a reaction with water at high temperatures. What is the balanced equation for this reaction?

2Mg(s) + H₂O(g) → Mg(OH)₂(s) + H₂(g) Mg(s) + 2H₂O(l) → Mg(OH)₂(aq) + H₂(g) Mg(s) + H₂O(g) → MgO(s) + H₂(g) Mg(s) + O₂(g) → MgO(s)

John wants to protect underwater pipelines from rusting by attaching a block of magnesium. Xinyi asks: Why does this work?

Magnesium acts as a sacrificial anode and corrodes instead of the iron. Magnesium forms a protective oxide layer over the iron surface. Magnesium increases the pH of water, preventing rust. Magnesium reacts with oxygen to produce a barrier of magnesium carbonate.

John and Xinyi are trapped in a room with a giant electronic Periodic Table. A voice booms: "Identify the Group and Period for the element with electronic configuration 2.8.7, or stay here forever!" What’s the correct answer?

Group V, Period 3 Group VII, Period 2 Group VII, Period 3 Group VIII, Period 3

John finds a glowing test tube containing iodine solution. A final screen pops up: "If bromine water is added to potassium iodide solution, what observable change happens?"

Effervescence observed Solution stays colourless Solution turns reddish-brown Yellow solid forms

To unlock the door, they need to answer: "Which statement best explains the decreasing reactivity down Group VII?"

Atoms get larger, harder to gain electrons Atoms get smaller, harder to attract electrons Higher proton number means stronger attraction More valence electrons down the group

An element, Q, forms a +7 oxidation state and a violet solution. It is used industrially as an oxidising agent. What can be inferred about Q?

Q is a halogen. Q is a noble gas. Q is a transition element. Q is in Group 1.

The electronic configuration of element Y is 2.8.7. Which statement best explains why it is highly reactive?

It forms metallic bonds with other atoms. It has a full outer shell and does not react easily. It loses one electron to form a stable ion. It readily gains one electron to complete its shell.

Xinyi investigates melting points of Period 3 elements. She notices Si has a much higher melting point than nearby elements. What best explains this observation?

Silicon contains free electrons. Silicon forms simple covalent molecules. Silicon has a giant covalent structure with strong bonds throughout. Silicon is a metal with giant metallic structure.

Which statement best compares a halogen and a noble gas in the same period?

Both have the same number of electron shells and are equally reactive. The halogen has lower electronegativity than the noble gas. The halogen is more reactive because it has incomplete outer shell. The noble gas is more reactive because it has more valence electrons.

Quiz: Chemistry - Patterns In The Periodic Table