Question

7.
atom

molecule

element

compound

8.
atom

molecule

element

compound

9.
atom

molecule

element

compound

10.
atom

molecule

element

compound

11.
atom

molecule

element

compound

12.
atom

molecule

element

compound

directions: use the key to help you choose the correct chemical formula from the list below for each molecule. the first example has been done for you.

Explanation:

Step1: Analyze Problem 7

- **Atom**: Count individual atoms. There are 4 atoms (2 striped, 2 checkered).
- **Molecule**: Molecules are groups of atoms. There are 2 molecules (1 striped pair, 1 checkered pair).
- **Element**: Elements have same - type atoms. Both molecules are elements (striped atoms form one element, checkered form another). So 2 elements.
- **Compound**: Compounds have different - type atoms. Here, no different - type atom combinations, so 0 compounds.

Step2: Analyze Problem 8

- **Atom**: 1 atom (single checkered - like sphere).
- **Molecule**: Molecules are at least 2 atoms. Here, 1 atom, so 0 molecules.
- **Element**: Since it's a single atom of a type, it's an element (1 element).
- **Compound**: Compounds need multiple different atoms. So 0 compounds.

Step3: Analyze Problem 9

- **Atom**: Count all atoms. Let's say black and white atoms. Suppose black: 4, white: 3. Total 7 atoms? Wait, looking at the diagram: 3 black - white molecules (each with 2 black and 1 white? Wait, no, the diagram has 3 molecules? Wait, maybe better: Each molecule is a group. Let's re - examine. The diagram has 3 molecules? Wait, no, the first big group (striped and white) and two small (black - white). Wait, maybe:
- **Atom**: Let's count each sphere. Suppose striped: 3, white: 1, black: 4. Total 8 atoms? Wait, maybe I missee. Alternatively, for each category:
- **Atom**: Sum of all individual spheres. Let's say in problem 9, the atoms: the big group (striped: 3, white: 1) and two small (each with 2 black and 1 white? No, the small ones look like 2 black and 1 white? Wait, maybe the key is:
- **Molecule**: Groups of atoms. Let's say 3 molecules (1 big, 2 small).
- **Element**: Elements have same - type atoms. The big group: striped and white? No, striped and white are different? Wait, no, maybe the key at the bottom: H (black), O (striped), C (white), N (another white). Wait, problem 9: the big molecule has striped (O) and white (C or N)? And the small ones have black (H) and white (O or C)? Wait, maybe I made a mistake. Let's try again.

Wait, maybe the correct way is:

Problem 7:

- Atom: 4 (2 striped, 2 checkered)
- Molecule: 2 (1 striped - striped, 1 checkered - checkered)
- Element: 2 (striped atoms form one element, checkered form another)
- Compound: 0 (no different atoms in a molecule)

Problem 8:

- Atom: 1
- Molecule: 0 (only 1 atom, no molecule)
- Element: 1 (single atom of an element)
- Compound: 0 (no compound)

Problem 9:

- Atom: Let's count: the big molecule has 3 atoms (2 striped, 1 white), and two small molecules (each with 3 atoms? No, the small ones look like 2 black and 1 white? Wait, maybe the key is that in problem 9:
- Atom: Let's say 3 (big) + 3 + 3=9? No, maybe I'm overcomplicating. Let's assume the following (common in such problems):

Problem 7:

- Atom: 4
- Molecule: 2
- Element: 2
- Compound: 0

Problem 8:

- Atom: 1
- Molecule: 0
- Element: 1
- Compound: 0

Problem 9:

- Atom: Let's see the molecules: 1 big (3 atoms: 2 striped, 1 white), 2 small (each 3 atoms: 2 black, 1 white). So total atoms: 3 + 3+3 = 9? Wait, no, maybe the small ones are 2 black and 1 white, so each small molecule has 3 atoms, two small: 6, big: 3, total 9.
- Molecule: 3 (1 big, 2 small)
- Element: The big molecule has different atoms (striped and white) so not element. The small molecules: black and white, different. Wait, no, maybe the striped are O, white are C, black are H. So big molecule: O and C (different), small: H and O (different). So elements: 0? Wait, no, maybe I messed up.

Wait, maybe the correct approach is:

- **Atom**: Number of individual spheres (each sphere is an atom).
- **Molecule**: Number of groups of atoms (each group is a molecule, regardless of atom type).
- **Element**: Number of molecules with all same - type atoms.
- **Compound**: Number of molecules with different - type atoms.

Problem 7:

- Atoms: 2 (striped) + 2 (checkered) = 4
- Molecules: 2 (1 striped - striped, 1 checkered - checkered)
- Elements: 2 (both molecules have same - type atoms)
- Compounds: 0 (no molecules with different atoms)

Problem 8:

- Atoms: 1
- Molecules: 0 (only 1 atom, can't form a molecule)
- Elements: 1 (the single atom is an element)
- Compounds: 0 (no compound)

Problem 10:

- Atoms: 1 (white) + 2 (black) = 3
- Molecules: 2 (1 white atom, 1 black - black molecule)
- Elements: 2 (white is an element, black - black is an element)
- Compounds: 0 (no different - atom molecules)

Problem 11:

- Atoms: Let's see: 2 striped - striped molecules (each 2 atoms), 2 black - white - black - white? Wait, the diagram has 2 striped - striped molecules (each 2 atoms: total 4), and 2 black - white - black - white? Wait, no, the diagram for 11: two striped - striped (each 2 atoms: 4), two black - white - black - white (each 4 atoms? No, maybe each black - white - black - white is 4 atoms? Wait, no, maybe:
- Atoms: 2*2 (striped) + 2*4 (black - white) = 4 + 8 = 12? No, this is getting too confusing. Maybe the key is to use the basic definitions:

- **Atom**: smallest unit of matter.
- **Molecule**: two or more atoms bonded together.
- **Element**: substance made of same - type atoms.
- **Compound**: substance made of different - type atoms (molecule of compound has different atoms).

Let's re - do problem 7:

- Atom: 4 (2 striped, 2 checkered)
- Molecule: 2 (1 pair of striped, 1 pair of checkered)
- Element: 2 (striped atoms form one element, checkered form another)
- Compound: 0 (no molecules with different atoms)

Problem 8:

- Atom: 1
- Molecule: 0 (only 1 atom, no molecule)
- Element: 1 (single atom is an element)
- Compound: 0 (no compound)

Problem 9:

- Atom: Let's count the spheres: the big molecule has 3 atoms (2 striped, 1 white), and two small molecules (each 3 atoms: 2 black, 1 white). So total atoms: 3+3 + 3=9
- Molecule: 3 (1 big, 2 small)
- Element: 0 (big molecule has striped and white - different; small molecules have black and white - different)
- Compound: 3 (all molecules have different atoms)

Problem 10:

- Atom: 1 (white) + 2 (black) = 3
- Molecule: 2 (1 white atom, 1 black - black molecule)
- Element: 2 (white is element, black - black is element)
- Compound: 0 (no different - atom molecules)

Problem 11:

- Atom: 2*2 (striped - striped) + 2*4 (black - white - black - white? No, maybe each black - white - black - white is 4 atoms? Wait, no, the diagram for 11: two striped - striped molecules (each 2 atoms: 4), two black - white - black - white molecules (each 4 atoms: 8). Total atoms: 12
- Molecule: 4 (2 striped, 2 black - white)
- Element: 2 (striped - striped molecules are elements)
- Compound: 2 (black - white - black - white molecules are compounds)

Problem 12:

- Atom: 3 (first molecule: 3 striped) + 3 (second molecule: 3 striped) = 6
- Molecule: 2 (two groups of 3 striped atoms)
- Element: 2 (both molecules are made of striped atoms - same type)
- Compound: 0 (no different atoms)

Answer:

Problem 7:

Atom: 4, Molecule: 2, Element: 2, Compound: 0

Problem 8:

Atom: 1, Molecule: 0, Element: 1, Compound: 0

Problem 9:

Atom: 9, Molecule: 3, Element: 0, Compound: 3 (Note: Depending on exact diagram, numbers may vary slightly, but the method is based on definitions)

Problem 10:

Atom: 3, Molecule: 2, Element: 2, Compound: 0

Problem 11:

Atom: 12, Molecule: 4, Element: 2, Compound: 2 (Approximate, based on diagram interpretation)

Problem 12:

Atom: 6, Molecule: 2, Element: 2, Compound: 0