Photosynthesis: the balanced equation and where the energy goes
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
Use this
Flow diagram (model, not to scale), drawn inside the chloroplast. Inputs in boxes on the left: 6CO₂; 6H₂O. Outputs in boxes on the right: C₆H₁₂O₆; 6O₂. A wavy arrow points into the reaction: light energy.
Ari reads 6CO₂ in the flow diagram. What does the 6 in front of CO₂ tell Ari?
- 6 molecules of carbon dioxide
- 6 carbon atoms in one CO₂ molecule
- 6 oxygen atoms in one CO₂ molecule
- 6 grams of carbon dioxide
Bo sees light energy on the left side of the photosynthesis equation. What kind of part is light energy?
- An input: energy that goes in and is stored
- An output: energy that the reaction releases
- An input: matter that adds atoms to glucose
- An output: energy that leaves as oxygen gas
Use the table
Formula card (model data, not to scale): one glucose molecule, C₆H₁₂O₆.
element subscript C 6 H 12 O 6 Jun reads the formula card for one glucose molecule. How many oxygen atoms does one molecule hold?
- 6 oxygen atoms
- 1 oxygen atom
- 24 oxygen atoms
- 12 oxygen atoms
Use this
Flow diagram (model, not to scale), drawn inside the chloroplast. Inputs in boxes on the left: 6CO₂; 6H₂O. Outputs in boxes on the right: C₆H₁₂O₆; 6O₂. A wavy arrow points into the reaction: light energy.
Kira reads 6CO₂ on the left. Atoms = coefficient × subscript. How many oxygen atoms is that?
- 8 oxygen atoms
- 2 oxygen atoms
- 12 oxygen atoms
- 6 oxygen atoms
The 6H₂O on the left holds 12 hydrogen atoms. Luz counts hydrogen atoms in C₆H₁₂O₆ and 6O₂ on the right. How many are there?
- 12 hydrogen atoms, all in the glucose
- 24 hydrogen atoms, since O₂ adds 12 more
- 6 hydrogen atoms, since half are lost
- 0 hydrogen atoms, since hydrogen is used up
Noah reads that plant cells carry out photosynthesis in chloroplasts. Which phrase tells what a chloroplast is?
- A cell part that turns carbon dioxide into oxygen gas
- A leaf opening that lets gases in and out
- A cell part that breaks glucose down to make ATP
- A cell part that carries out photosynthesis
Pia reads that plants are photoautotrophs. Which phrase tells what a photoautotroph is?
Use the picture in question 6.
- An organism that builds its body from soil it takes in
- An organism that makes its own food using light
- An organism that gets energy from inorganic chemicals
- An organism that relies on sugars made by other organisms
Use this
Flow diagram (model, not to scale), drawn inside the chloroplast. Inputs in boxes on the left: 6CO₂; 6H₂O. Outputs in boxes on the right: C₆H₁₂O₆; 6O₂. Letter D marks a wavy arrow touching the reaction; its label is blank.
Ren reads a flow diagram of photosynthesis with a blank wavy arrow D touching the reaction. Which label fits D?
- No energy moves: CO₂ and glucose hold equal energy
- Light energy in: it becomes the atoms of the glucose
- Energy out: released as the glucose forms
- Light energy in: taken in and stored in the glucose bonds
Flow diagram (model, not to scale), drawn inside the chloroplast. Tala counts carbon atoms in a flow diagram. Box H gives the number of carbon atoms in the glucose made. What number goes in H?
- 1 carbon atom, since there is one glucose
- 0 carbon atoms, since carbon is used up
- 12 carbon atoms, since the reaction makes more
- 6 carbon atoms, matching the 6 in the CO₂
Use this
Flow diagram (model, not to scale), drawn inside the chloroplast. Inputs in boxes on the left: 6CO₂; 6H₂O. Outputs in boxes on the right: C₆H₁₂O₆; 6O₂. A wavy arrow points into the reaction: light energy.
Zee reads that light energy goes into photosynthesis. Where does that energy end up afterward?
- Added to the glucose as extra atoms of light
- Gone, since light cannot be kept
- Carried away by the oxygen gas
- Stored in the bonds of the glucose