Chemistry of Food: Grade 9 Student Guide
Chemistry of Food
A Grade 9 Science Unit Guide · Aligned to NGSS, Common Core, and USDA/FDA
Guidelines
Course: Physical Science / Integrated Science (Grade 9) · Length: 6 weeks · Student
Name: ____________ · Date: ____________
1. Unit Overview
Every bite of food is chemistry. Bread rises because of gas produced by yeast. Apples
turn brown because of oxidation. Milk turns into cheese because proteins change shape.
In this unit you will learn how atoms and molecules make up food, how cooking changes
them, how your body uses them for energy, and how chemistry keeps food safe.
Essential Questions
1. What is food made of at the atomic and molecular level?
2. How do chemical and physical changes transform ingredients when we cook?
3. How does the body turn food into energy and building materials?
4. How can we use chemistry to keep food safe and make healthy choices?
2. Standards Alignment
Standard What It Means in This Unit
NGSS HS-PS1-1 Use the periodic table to predict how atoms in food
molecules bond
NGSS HS-PS1-2 Explain outcomes of simple reactions (baking soda
+ acid) using electron patterns
NGSS HS-PS1-3 Relate properties of substances (melting,
solubility) to forces between particles
NGSS HS-PS1-4 Model energy release or absorption in reactions
(cold packs, burning food)
NGSS HS-PS1-5 Explain how temperature and concentration
change reaction rate
Page 1 of 18
,Chemistry of Food: Grade 9 Student Guide
Standard What It Means in This Unit
NGSS HS-PS1-7 Use mathematical representations to show
conservation of mass
NGSS HS-LS1-6 Show how carbon, hydrogen, and oxygen form
sugars, fats, and amino acids
NGSS HS-LS1-7 Describe cellular respiration as breaking down
food to release energy
CCSS ELA RST.9-10.3, .7 Follow multi-step procedures; translate between
text, tables, and graphs
CCSS Math HSN-Q.A.1–3 Use units and appropriate precision in
measurements
USDA/FDA Dietary Guidelines for Americans, MyPlate, and the
Nutrition Facts label
3. Learning Objectives
By the end of this unit, you will be able to:
Identify the main elements and compounds found in food
Classify food as an element, compound, or mixture, and describe its state of matter
Explain the roles of water, pH, acids, and bases in food
Describe the structure and function of carbohydrates, lipids, proteins, vitamins, and
minerals
Distinguish physical changes from chemical changes in cooking
Calculate Calories and read a Nutrition Facts label
Explain the chemistry of food preservation and food safety
Safely design, carry out, and report on a food chemistry investigation
Page 2 of 18
, Chemistry of Food: Grade 9 Student Guide
4. Unit 1: Matter and Atoms in Food
4.1 The Elements of Food
About 96% of the mass of living things, and therefore of food, comes from just four
elements, often remembered as CHON: Carbon, Hydrogen, Oxygen, Nitrogen.
Phosphorus and Sulfur join them in many biological molecules (CHONPS).
Element Symbol Where It Shows Up in Food
Carbon C Backbone of every sugar, fat, and protein
Hydrogen H Water, sugars, fats, acids
Oxygen O Water, sugars, proteins; the gas that causes
browning
Nitrogen N Proteins and DNA (meat, beans, eggs)
Phosphorus P Bones, milk, ATP energy molecules
Sulfur S Egg yolks, garlic, onions (the smell!)
Calcium Ca Milk, cheese, leafy greens (bones and teeth)
Iron Fe Red meat, spinach (carries oxygen in blood)
Sodium and Chlorine Na, Cl Table salt (NaCl), a compound of both
4.2 Atoms, Bonds, and Molecules
Atoms bond by sharing or transferring valence electrons.
Covalent bonds (sharing electrons): water (H₂O), glucose (C₆H₁₂O₆), carbon dioxide
(CO₂)
Ionic bonds (transferring electrons): table salt (NaCl), baking soda (NaHCO₃)
Key formulas to know
Substance Formula Type
Water H₂O Covalent compound
Table sugar (sucrose) C₁₂H₂₂O₁₁ Covalent compound
Page 3 of 18
Chemistry of Food
A Grade 9 Science Unit Guide · Aligned to NGSS, Common Core, and USDA/FDA
Guidelines
Course: Physical Science / Integrated Science (Grade 9) · Length: 6 weeks · Student
Name: ____________ · Date: ____________
1. Unit Overview
Every bite of food is chemistry. Bread rises because of gas produced by yeast. Apples
turn brown because of oxidation. Milk turns into cheese because proteins change shape.
In this unit you will learn how atoms and molecules make up food, how cooking changes
them, how your body uses them for energy, and how chemistry keeps food safe.
Essential Questions
1. What is food made of at the atomic and molecular level?
2. How do chemical and physical changes transform ingredients when we cook?
3. How does the body turn food into energy and building materials?
4. How can we use chemistry to keep food safe and make healthy choices?
2. Standards Alignment
Standard What It Means in This Unit
NGSS HS-PS1-1 Use the periodic table to predict how atoms in food
molecules bond
NGSS HS-PS1-2 Explain outcomes of simple reactions (baking soda
+ acid) using electron patterns
NGSS HS-PS1-3 Relate properties of substances (melting,
solubility) to forces between particles
NGSS HS-PS1-4 Model energy release or absorption in reactions
(cold packs, burning food)
NGSS HS-PS1-5 Explain how temperature and concentration
change reaction rate
Page 1 of 18
,Chemistry of Food: Grade 9 Student Guide
Standard What It Means in This Unit
NGSS HS-PS1-7 Use mathematical representations to show
conservation of mass
NGSS HS-LS1-6 Show how carbon, hydrogen, and oxygen form
sugars, fats, and amino acids
NGSS HS-LS1-7 Describe cellular respiration as breaking down
food to release energy
CCSS ELA RST.9-10.3, .7 Follow multi-step procedures; translate between
text, tables, and graphs
CCSS Math HSN-Q.A.1–3 Use units and appropriate precision in
measurements
USDA/FDA Dietary Guidelines for Americans, MyPlate, and the
Nutrition Facts label
3. Learning Objectives
By the end of this unit, you will be able to:
Identify the main elements and compounds found in food
Classify food as an element, compound, or mixture, and describe its state of matter
Explain the roles of water, pH, acids, and bases in food
Describe the structure and function of carbohydrates, lipids, proteins, vitamins, and
minerals
Distinguish physical changes from chemical changes in cooking
Calculate Calories and read a Nutrition Facts label
Explain the chemistry of food preservation and food safety
Safely design, carry out, and report on a food chemistry investigation
Page 2 of 18
, Chemistry of Food: Grade 9 Student Guide
4. Unit 1: Matter and Atoms in Food
4.1 The Elements of Food
About 96% of the mass of living things, and therefore of food, comes from just four
elements, often remembered as CHON: Carbon, Hydrogen, Oxygen, Nitrogen.
Phosphorus and Sulfur join them in many biological molecules (CHONPS).
Element Symbol Where It Shows Up in Food
Carbon C Backbone of every sugar, fat, and protein
Hydrogen H Water, sugars, fats, acids
Oxygen O Water, sugars, proteins; the gas that causes
browning
Nitrogen N Proteins and DNA (meat, beans, eggs)
Phosphorus P Bones, milk, ATP energy molecules
Sulfur S Egg yolks, garlic, onions (the smell!)
Calcium Ca Milk, cheese, leafy greens (bones and teeth)
Iron Fe Red meat, spinach (carries oxygen in blood)
Sodium and Chlorine Na, Cl Table salt (NaCl), a compound of both
4.2 Atoms, Bonds, and Molecules
Atoms bond by sharing or transferring valence electrons.
Covalent bonds (sharing electrons): water (H₂O), glucose (C₆H₁₂O₆), carbon dioxide
(CO₂)
Ionic bonds (transferring electrons): table salt (NaCl), baking soda (NaHCO₃)
Key formulas to know
Substance Formula Type
Water H₂O Covalent compound
Table sugar (sucrose) C₁₂H₂₂O₁₁ Covalent compound
Page 3 of 18
