Atoms and Elements Atoms are the basic units of all matter.

Atoms and ElementsChapter 6: The Chemistry of Life

Atoms are the basic units of

all matter.

1.Protons (+) 2.Neutrons (0)3.Electrons (-)

Atoms are composed of 3

sub-atomic particles:

An atom is the smallest

particle of an element.

Elements

An element is a substance that can not be broken down into simpler chemical substances.

Everything is made of substances called elements.

Each element is identified by a one- or two-letter abbreviation

called a symbol.

Atomic numberThe atomic number is

equal to the number of protons that an atom

has.

Ex. Silver has an atomic number of 47 and therefore has 47 protons

Atoms always contain the same number of protons

and electronsAtomic # = protons = electrons

Atomic MassThe atomic mass is the number of

protons and neutrons added together.

How do you figure how many neutrons there are?

Atomic mass - atomic number = number of neutrons!

The Fab Five Elements

In Biology this year, we will be focusing on 5 main elements.

They are…

Carbon Hydrogen Oxygen Nitrogen Phosphorus

Notice just how much of the human body they compose

That’s 96.8% of your total body composition!

Carbon•Atomic Number: 6•Atomic Mass: 12.01•Carbon is the basis for organic organisms as it occurs in all living things.•Makes up about 18% of human bodies• Examples: found in carbohydrates, lipids, proteins and nucleic acids

Carbon in Chemical StructuresCarbon is so common in living organisms that they can sometimes be omitted to save time. Anywhere there is a corner without a letter, that means a carbon is actually there.

Carbons are representedBy the letter

C

Hydrogen•Atomic Number: 1•Atomic Mass: 1.01•Hydrogen is the most abundant element in the universe•Makes up about 10% of human bodies•Examples: found in carbohydrates, lipids, proteins and nucleic acids

Hydrogen is

represented

By the letter H

Hydrogen in Chemical Structures

Oxygen Atomic Number: 8 Atomic Mass: 15.99 Animals and plants require Oxygen

for respiration Makes up about 65% of human

bodies Examples: found in carbohydrates,

lipids, proteins and nucleic acids

Oxygen in Chemical Structures

Oxygen is represente

dBy the

letter O

Nitrogen Atomic Number: 7 Atomic Mass: 14.01 Nitrogen gas (N2) makes up

78.1% of the volume of the Earth's air.

Makes up about 3% of human bodies

Examples: found in proteins and nucleic acids

Nitrogen in Chemical Structures

Nitrogen is representedBy the letter

N

Phosphorus Atomic Number: 15 Atomic Mass: 30.97 Important for proper

skeletal and nervous system function

Makes up about 1% of human bodies

Examples: found in nucleic acids

Phosphorus in Chemical Structures

Phosphorus is

represented

By the letter P

Directions: Label each of the Fab Five Elements in the chemical

compound (Adenosine Triphosphate a.k.a

ATP) below.

Directions: Label each of the Fab Five Elements in the chemical

compound (glucose) below.