Question

a teacher asks the students to classify the substances listed in the table as elements, compounds, or mixtures.
substances | formula
--- | ---
sucrose | c₁₂h₂₂o₁₁
ammonia | nh₃
water | h₂o
a student claims that all of the substances are compounds. which statement correctly describes the student’s claim?

• the student’s claim is correct because the atoms in the substances are chemically combined to form a compound.
• the student’s claim is correct because a substance that contains more of 2 of the same atom is a compound.
• the student’s claim is incorrect because the atoms in the substances are physically combined to form a mixture.
• the student’s claim is incorrect because a substance that contains more than one element is always a mixture.

Explanation:

1. Analyze each option:

• Option 1: Compounds are substances where atoms are chemically combined. Sucrose ($C_{12}H_{22}O_{11}$), ammonia ($NH_3$), and water ($H_2O$) are all compounds as their atoms are chemically bonded. So if the student claims all are compounds, this option supports the claim correctly.
• Option 2: A compound is not defined by having more of the same atom. A compound has different atoms chemically bonded. So this reasoning is wrong.
• Option 3: The substances are not mixtures (mixtures have physically combined components, but these are pure substances with chemical bonds). So this is wrong.
• Option 4: A substance with more than one element can be a compound (chemically bonded) not always a mixture. So this is wrong.

Answer:

The student's claim is correct because the atoms in the substances are chemically combined to form a compound.