H
C
N
O
P
S
Se
LIFE'S BUILDING BLOCKS • ORGANIC ELEMENTS

NON-METALS

The essence of life itself - from the oxygen we breathe to the carbon in our DNA, these elements form the foundation of all biological processes

96%
Of Human Body
78%
N₂ in Air
10M+
Organic Compounds

The Chemistry of Life

Non-metals are the fundamental elements of life, comprising the vast majority of all living matter. These elements form covalent bonds, creating the complex molecules essential for biological processes. Carbon's unique ability to form four bonds creates the backbone of organic chemistry, while hydrogen, nitrogen, and oxygen complete the quartet that makes up 96% of all living organisms.

From the water molecule that sustains all life to the complex proteins that catalyze biological reactions, from the DNA that carries genetic information to the atmospheric gases that maintain Earth's climate, non-metals are not just important - they are indispensable. Their unique properties enable the chemistry that distinguishes living from non-living matter.

The Non-Metal Elements

1
H
Hydrogen
1.008 u
6
C
Carbon
12.011 u
7
N
Nitrogen
14.007 u
8
O
Oxygen
15.999 u
15
P
Phosphorus
30.974 u
16
S
Sulfur
32.06 u
34
Se
Selenium
78.96 u

Earth's Atmosphere

Nitrogen (N₂) - 78%
Oxygen (O₂) - 21%
Other Gases - 1%

Non-metals dominate Earth's atmosphere, with nitrogen and oxygen alone comprising 99% of the air we breathe. This delicate balance has been maintained for millions of years, enabling the evolution of complex life forms.

Essential Life Cycles

Carbon Cycle
Carbon cycles through the atmosphere, biosphere, and geosphere. Plants absorb CO₂ during photosynthesis, animals consume plants, and decomposition returns carbon to the soil and atmosphere.
Nitrogen Cycle
Nitrogen fixation by bacteria converts atmospheric N₂ into ammonia, which plants use to build proteins. Decomposition and denitrification complete the cycle back to atmospheric nitrogen.
Water Cycle
Water (H₂O) evaporates from oceans and lakes, forms clouds, falls as precipitation, and flows back to the oceans, carrying nutrients and enabling all biochemical reactions.
Phosphorus Cycle
Phosphorus moves through rocks, water, soil, and organisms. Essential for DNA, RNA, and ATP, it's often the limiting nutrient in ecosystems.

Key Organic Molecules

H₂O
Water
Universal solvent, essential for all life
CO₂
Carbon Dioxide
Plant food, greenhouse gas, pH buffer
CH₄
Methane
Natural gas, simplest hydrocarbon
C₆H₁₂O₆
Glucose
Primary energy source for cells
NH₃
Ammonia
Fertilizer, cleaning agent, nitrogen source
H₂SO₄
Sulfuric Acid
Industrial catalyst, battery acid

Properties Comparison

Element Symbol State at 20°C Electronegativity Common Forms Biological Role
Hydrogen H Gas 2.20 H₂, H₂O Water, Organic molecules
Carbon C Solid 2.55 Diamond, Graphite All organic compounds
Nitrogen N Gas 3.04 N₂, NH₃, NO₃⁻ Proteins, DNA
Oxygen O Gas 3.44 O₂, O₃, H₂O Respiration, Water
Phosphorus P Solid 2.19 White, Red, Black DNA, ATP, Bones
Sulfur S Solid 2.58 S₈, SO₂, H₂S Amino acids, Vitamins

Industrial Importance

Ammonia Production

The Haber process combines nitrogen and hydrogen to produce ammonia, the foundation of modern agriculture through fertilizer production.

Petroleum Chemistry

Hydrocarbons from crude oil are refined into fuels, plastics, and thousands of organic chemicals essential to modern life.

Medical Oxygen

Pure oxygen is vital for medical treatments, from emergency care to hyperbaric therapy, saving millions of lives annually.

Carbon Materials

From carbon fiber composites to graphene and carbon nanotubes, carbon allotropes are revolutionizing materials science.

Explore More

View Periodic Table Explore Halogens