Page 31 - Science Course 2 (Book 1)

Human Body: Organic and Inorganic Substances
Lesson 1

Compounds can be made by binding elements
together in two different ways—ionic or covalent
bonds.
In this topic, you will learn the following
lessons: Ionic bonds are formed when electrons travel from
one element to another.
Mo.2-L1a: How Does Water Dissolve Ionic
Substances?
Mo.2-L1b: Why are Organic Compounds atoms
Important? –

+ +
Mo2-L1a How Does Water Dissolve Ionic –
Substances?

KEY CONCEPTS: Transfer of
1. How does water help the body obtain ionic Electron
substances?
–
Let’s Begin + +

–
Life and Chemistry
Positive Negative
During a chemical reaction, bonds are broken and ion ion
new bonds are formed. ionic bond

Chemical reactions that occur in the human body
take place in the body’s cells and are essential for atoms
human life. – –

+ +
N + H + H + H NH + NH
2 2 2 2 3 3

Sharing of
C + CO CO + CO
2 Electrons

–
N + O NO + NO
2 2
+ +
–
Elements and Compounds
Molecule
Elements are substances that cannot be broken
down or transformed into another element during a covalent bond
chemical reaction.

Six elements—carbon, oxygen, hydrogen, nitrogen, Covalent bonds are formed when the electrons in
calcium, and phosphorus—make up 99 percent of each element are shared.
your body’s mass.
Inorganic compounds are substances that do
not contain carbon-hydrogen bonds.

Water and oxygen Oxygen Water
gas are inorganic
compounds that
humans need to
survive.
O H O
2 2
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