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The chemical context of life

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Key concepts

Matter consists of chemical elements in pure

form and in combinations called compounds

An elements properties depend on the

structure of its atoms

The formation and function of molecules

depend on chemical bonding between atoms

Chemical reactions make and break chemicalbonds

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Matter consists of chemical

elements in pure form and

combinations called compounds

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Matter consists of chemical

elements in pure form and

combinations called compounds

Something that has mass and occupies space

Matter consists of atoms

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Matter consists of chemical

elements in pure form and

combinations called compounds

Something that has mass and occupies space

Matter consists of atoms

What are atoms?

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Matter consists of chemical

elements in pure form and

combinations called compounds

Something that has mass and occupies space

Matter consists of atomsAtoms are the fundamental building block of all substances.

The smallest unit of matter that retains the properties of an element.

What is an element?

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Matter consists of chemical

elements in pure form and

combinations called compounds

Something that has mass and occupies space

Matter consists of atomsAtoms are the fundamental building block of all substances.

The smallest unit of matter that retains the properties of an element.

An element is a substance thatcannot be broken down into

other substances by chemical

reaction.

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Matter consists of chemical

elements in pure form and

combinations called compounds

Something that has mass and occupies space

Matter consists of atomsAtoms are the fundamental building block of all substances.

The smallest unit of matter that retains the properties of an element.

An element is a substance thatcannot be broken down into

other substances by chemical

reaction.

Why?

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Matter consists of chemical

elements in pure form and

combinations called compounds

Each element iscomposed on a

single type of atom

Compounds aremade of more than

one element in a

fixed ratio

goldhydrogen and oxygen

sodium and chloride

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Matter consists of

chemical elements

in pure form andcombinations

called compounds

Whether they are in compounds or in

pure form, there are relatively few

elements in living organisms

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Matter consists of chemical

elements in pure form and

combinations called compounds

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An elements properties depend on

the structure of its atoms

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An elements properties depend on

the structure of its atoms

What do we mean by properties?

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An elements properties depend on

the structure of its atomsProperties-melting point, bonding, and density are commonexamples.

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An elements properties depend on

the structure of its atomsAtomic structure

Nucleus

Contains:

Protons

Neutrons

Electron cloud

Contains:

Electrons

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An elements properties depend on

the structure of its atomsAtomic structure

Nucleus

Contains:

Protons

Neutrons

Electron cloud

Contains:

Electrons

All atoms of the same element will have the same number of protons (Atomic number)

He2

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An elements properties depend on

the structure of its atoms

Atomic structure

Nucleus

Contains:

Protons

Neutrons

Electron cloud

Contains:

Electrons

All atoms of the same element will have the same number of protons (Atomic number)

The number of neutrons typically equals the number of protons

He2

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An elements properties depend on

the structure of its atoms

Atomic structure

Nucleus

Contains:

Protons

Neutrons

Electron cloud

Contains:

Electrons

All atoms of the same element will have the same number of protons (Atomic number)

The number of neutrons typically equals the number of protons

Mass numberis the number of protons + number of neutrons

He2

4

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An elements properties depend on

the structure of its atoms

Atomic structure

Nucleus

Contains:

Protons

Neutrons

Electron cloud

Contains:

Electrons

All atoms of the same element will have the same number of protons (Atomic number)

The number of neutrons typically equals the number of protons

Mass numberis the number of protons + number of neutrons

The number of electrons typically equals the number of protons

He2

4

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What is the atomic number of Aluminum?

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How many protons does Lithium have?

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What is the mass number of Chloride?

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An elements properties depend on

the structure of its atoms

Atomic structure

Nucleus

Contains:

Protons

Neutrons

Electron cloud

Contains:

Electrons

All atoms of the same element will have the same number of protons (Atomic number)

The number of neutrons typically equals the number of protons (not forisotopes)

Mass numberis the number of protons + number of neutrons

The number of electrons typically equals the number of protons

He2

3

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An elements properties depend on

the structure of its atoms

Atomic structure

Nucleus

Contains:

Protons

Neutrons

Electron cloud

Contains:

Electrons

All atoms of the same element will have the same number of protons (Atomic number)

The number of neutrons typically equals the number of protons (not forisotopes)

Mass numberis the number of protons + number of neutrons

The number of electrons typically equals the number of protons (not forions)

He2

4 +

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An elements properties depend on

the structure of its atoms

Focusing on electrons-The chemical behavior of an atom isdetermined by the distribution of its electrons

Atomic structure

Hydrogen

1H

Lithium

3LiBeryllium

4BeBoron

5BCarbon

6CNitrogen

7NOxygen

8OFluorine

9FNeon

10Ne

Helium

2He

Firstshell

Secondshell

Thirdshell

Sodium

11NaMagnesium

12MgAluminum

13AlSilicon

14SiPhosphorus

15PSulfur

16SChlorine

17ClArgon

18Ar

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An elements properties depend on

the structure of its atoms

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The formation and function of

molecules depend on chemical

bonding between atomsDifferent types of bondsCovalent bonds (strongest) - involves the sharing of electrons (i.e.

H2)

Electrons may be spread equally across the bond (non-polarbond)

Electrons may not be spread equally across the bond (polar

bond)

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The formation and function of

molecules depend on chemical

bonding between atoms

Naturalendorphin

EndorphinreceptorsBrain cell

Binding to endorphin receptors

Morphine

(b)

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The formation and function of

molecules depend on chemical

bonding between atomsDifferent types of bondsCovalent bonds (strongest) - involves the sharing of electrons

(i.e. H2)

Electrons may be spread equally across the bond (non-polar bond)

Electrons may not be spread equally across the bond

(polar bond)

Ionic bonds- Charge-charge interactions

An interaction between a positive and negative chargeCan form after one atoms strips a valence electron from

another (ie. NaCl)

Forms salts

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The formation and function of

molecules depend on chemical

bonding between atoms

Ionic bond

Electrontransfer

forms ions

Na

Sodium atom

Cl

Chlorine atom

Na+

Sodium ion

(a cation)

Cl

Chloride ion

(an anion)

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Which elements will most likely

form an ionic bond?

a. Li and F

b. C and O

c. N and O

d. Si and Cl

e. H and H

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The formation and function of

molecules depend on chemical

bonding between atomsDifferent types of bonds (weak)

Hydrogen bonds- involve polar covalent bonds,

form when a hydrogen atom is bonded to a moreelectronegative atom

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The formation and function of

molecules depend on chemical

bonding between atomsDifferent types of bonds (weak)

Hydrogen bonds- involve polar covalent bonds,

form when a hydrogen atom is bonded to a moreelectronegative atom

This impacts the properties of water!

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The formation and function of

molecules depend on chemical

bonding between atomsDifferent types of bonds (weak)

Hydrogen bonds- involve polar covalent bonds,

form when a hydrogen atom is bonded to a moreelectronegative atom

Vander Waals interactions- involve non-polar

covalent bonds, occur when an electron

accumulation arises by chance

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The formation and function of

molecules depend on chemical

bonding between atoms

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Chemical reactions make and

break chemical bonds

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Chemical reactions make and

break chemical bonds

Chemical reaction- making a breaking of

chemical bonds leading to changes in the

composition of matter

6 CO2 + 6 H2O C6H12O6 + 6O2

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Chemical reactions make and

break chemical bonds

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Key concepts

Matter consists of chemical elements in pure

form and in combinations called compounds

An elements properties depend on the

structure of its atoms

The formation and function of molecules

depend on chemical bonding between atoms

Chemical reactions make and break chemicalbonds

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