Question

activity: understanding elements, compounds and mixtures at the particle level. (this should be a review of grade 7 science) 1. match the boxes on the right with the descriptions below. ____ 1. element __ 2. compound __ 3. mixtures of elements __ 4. mixtures of compounds __ 5. mixtures of elements and compounds 2. which of the boxes on the right contain (there may be more than one): __ 6. only atoms, no molecules __ 7. only molecules no individual atoms ____ 8. molecules and individual atoms a diagram of particles, b diagram of particles, c diagram of particles, d diagram of particles, e diagram of particles

Explanation:

Part 1: Matching Descriptions to Boxes

1. Element

An element consists of only one type of atom. Box B has only one type of particle (triangles), so it represents an element.

2. Compound

A compound consists of molecules made of two or more different types of atoms bonded together. Box C has molecules with two different atoms (e.g., one type of atom and another type in each molecule), so it represents a compound.

3. Mixtures of Elements

A mixture of elements has two or more different types of atoms (not bonded as molecules). Box A has two types of atoms (circles of different colors), so it represents a mixture of elements.

4. Mixtures of Compounds

A mixture of compounds has two or more different types of molecules (each molecule is a compound). Box E has multiple types of molecules (e.g., different combinations of atoms), so it represents a mixture of compounds.

5. Mixtures of Elements and Compounds

A mixture of elements and compounds has both individual atoms (elements) and molecules (compounds). Box D has individual atoms (square, hexagon) and molecules (e.g., the two - atom and three - atom groups), so it represents a mixture of elements and compounds.

Part 2: Identifying Particles in Boxes

6. Only atoms, no molecules

Boxes with only individual atoms (no molecules) are those with single - type or multiple - type atoms not bonded. Box A (two types of atoms, no molecules) and Box B (one type of atom, no molecules) meet this.

7. Only molecules, no individual atoms

Boxes with only molecules (no free atoms) are those where all particles are molecules. Box C (molecules of a compound) and Box E (molecules of different compounds) meet this.

8. Molecules and individual atoms

Boxes with both molecules and individual atoms are those with a mix of free atoms and molecules. Box D has individual atoms (square, hexagon) and molecules (e.g., the two - atom and three - atom groups), so it meets this.

Final Answers

1. 1 - B; 2 - C; 3 - A; 4 - E; 5 - D
2. 6 - A, B; 7 - C, E; 8 - D

Answer:

Part 1: Matching Descriptions to Boxes

1. Element

An element consists of only one type of atom. Box B has only one type of particle (triangles), so it represents an element.

2. Compound

A compound consists of molecules made of two or more different types of atoms bonded together. Box C has molecules with two different atoms (e.g., one type of atom and another type in each molecule), so it represents a compound.

3. Mixtures of Elements

A mixture of elements has two or more different types of atoms (not bonded as molecules). Box A has two types of atoms (circles of different colors), so it represents a mixture of elements.

4. Mixtures of Compounds

A mixture of compounds has two or more different types of molecules (each molecule is a compound). Box E has multiple types of molecules (e.g., different combinations of atoms), so it represents a mixture of compounds.

5. Mixtures of Elements and Compounds

A mixture of elements and compounds has both individual atoms (elements) and molecules (compounds). Box D has individual atoms (square, hexagon) and molecules (e.g., the two - atom and three - atom groups), so it represents a mixture of elements and compounds.

Part 2: Identifying Particles in Boxes

6. Only atoms, no molecules

Boxes with only individual atoms (no molecules) are those with single - type or multiple - type atoms not bonded. Box A (two types of atoms, no molecules) and Box B (one type of atom, no molecules) meet this.

7. Only molecules, no individual atoms

Boxes with only molecules (no free atoms) are those where all particles are molecules. Box C (molecules of a compound) and Box E (molecules of different compounds) meet this.

8. Molecules and individual atoms

Boxes with both molecules and individual atoms are those with a mix of free atoms and molecules. Box D has individual atoms (square, hexagon) and molecules (e.g., the two - atom and three - atom groups), so it meets this.

Final Answers

1. 1 - B; 2 - C; 3 - A; 4 - E; 5 - D
2. 6 - A, B; 7 - C, E; 8 - D