Question

1 multiple choice 1 point
the ______ is a unit of measure for the number of atoms in a sample.
○ mole
○ temperature
○ ionic radius
○ joule

2 multiple choice 1 point
______ reactions occur when a single reactant breaks into multiple products.
○ single replacement
○ double replacement
○ decomposition
○ combination

Explanation:

Question 1

To solve this, we analyze each option:

• "mole" is the unit for the amount of substance (number of atoms/molecules in a sample).
• "temperature" measures heat intensity, not atom count.
• "ionic radius" measures ion size.
• "joule" is for energy. So the correct option is "mole".

Analyze reaction types:

• "Single replacement" involves one element replacing another.
• "Double replacement" involves two compounds exchanging ions.
• "Decomposition" is when one reactant breaks into multiple products (matches the description).
• "Combination" is multiple reactants forming one product. So the correct option is "Decomposition".

Answer:

A. mole

Question 2