5
practice testMultiple Choice

Practice Test

Question 5 • Chemistry

When a strip of magnesium metal is touched to a flame, a bright light and a whitish substance are produced. Why is the burning of magnesium considered a chemical change?

Answer
A
because a new substance is formed
B
because the metal is malleable
C
because the metal reaches a high temperature
D
because the metal begins to melt

Explanation

A chemical change produces one or more new substances. When magnesium burns, it reacts with oxygen and forms a whitish substance called magnesium oxide, so the change is chemical. Reaching a high temperature or melting alone would not show that a new substance formed.

AI-written and checked against the verified answer.

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