| Nonmetals |
Hydrogen (H) |
None |
0.000055% (in Earth's crust) |
Trace |
+1, -1 |
Hydrogen is abundant in stars, potentially explosive in certain conditions. |
1s¹ |
Used in fuel cells, rockets |
2H₂ + O₂ → 2H₂O |
Research on hydrogen fuel as an alternative to fossil fuels |
Handle with care, flammable gas |
Non-toxic, but highly flammable |
| Oxygen (O) |
O-16, O-17, O-18 |
21% (in the atmosphere) |
0.8% (in human body) |
-2 |
Essential for life; high reactivity can cause environmental damage in large amounts. |
1s² 2s² 2p⁴ |
Used in respiration, combustion, and water purification |
2Mg + O₂ → 2MgO |
Research on oxygen therapy for medical applications |
Oxygen is highly reactive; use in well-ventilated areas |
Necessary for life, can cause oxidative stress in excess |
| Carbon (C) |
C-12, C-13, C-14 |
0.02% (in Earth's crust) |
18.5% (in human body) |
-4, +4 |
Carbon dioxide contributes to greenhouse gases. |
1s² 2s² 2p² |
Key component of organic compounds |
C + O₂ → CO₂ |
Carbon capture research, carbon-based nanomaterials |
Handle with care, avoid inhaling soot or carbon dust |
Carbon monoxide poisoning is a health risk; carbon dioxide is a greenhouse gas |
| Alkali Metals |
Lithium (Li) |
Li-6, Li-7 |
0.002% (in Earth's crust) |
Trace |
+1 |
Used in batteries, reactive with water |
[He] 2s¹ |
Used in rechargeable batteries, psychiatric medicine |
2Li + 2H₂O → 2LiOH + H₂ |
Research on lithium-ion batteries |
Store in oil, highly reactive |
Can affect neurological functions in high doses |
| Sodium (Na) |
Na-23 |
2.36% (in Earth's crust) |
0.05% (in human body) |
+1 |
Highly reactive, especially with water |
[Ne] 3s¹ |
Used in street lighting, soap making |
2Na + 2H₂O → 2NaOH + H₂ |
Research on sodium-based batteries for energy storage |
Handle with gloves, highly reactive with water |
Excess sodium can cause high blood pressure |
| Potassium (K) |
K-39 |
2.6% (in Earth's crust) |
0.19% (in human body) |
+1 |
Essential for plant growth |
[Ar] 4s¹ |
Used in fertilizers, fireworks |
2K + 2H₂O → 2KOH + H₂ |
Research on potassium channels in nerve cells |
Store away from water and moisture |
Deficiency can cause muscle weakness, excess can cause heart issues |
| Rubidium (Rb) |
Rb-85, Rb-87 |
0.01% (in Earth's crust) |
Trace |
+1 |
Highly reactive, used in atomic clocks |
[Kr] 5s¹ |
Used in fireworks, medical imaging |
2Rb + 2H₂O → 2RbOH + H₂ |
Research on rubidium-based quantum computing |
Store in inert atmosphere, reacts violently with water |
Low toxicity but reactive in air |
| Cesium (Cs) |
Cs-133 |
0.00019% (in Earth's crust) |
Trace |
+1 |
Highly reactive, used in atomic clocks |
[Xe] 6s¹ |
Used in atomic clocks, drilling fluids |
2Cs + 2H₂O → 2CsOH + H₂ |
Research on cesium-based ion thrusters |
Store in vacuum or mineral oil |
Highly reactive, forms strong alkaline solutions |
| Halogens |
Fluorine (F) |
F-19 |
0.00006% (in Earth's crust) |
Trace |
-1 |
Highly reactive, used in Teflon coatings |
1s² 2s² 2p⁵ |
Used in toothpaste, Teflon |
2F₂ + 2Na → 2NaF |
Research on fluorine compounds in pharmaceuticals |
Handle with extreme caution, corrosive |
Highly toxic, can cause severe burns |
| Chlorine (Cl) |
Cl-35, Cl-37 |
0.0001% (in Earth's crust) |
0.0007% (in human body) |
-1 |
Chlorine is toxic in high concentrations |
[Ne] 3s² 3p⁵ |
Used in disinfectants, bleach, water treatment |
2Na + Cl₂ → 2NaCl |
Research on chlorine in environmental disinfection |
Handle with care, toxic gas |
Highly toxic; can irritate respiratory system |
| Bromine (Br) |
Br-79, Br-81 |
0.0003% (in Earth's crust) |
Trace |
-1 |
Liquid at room temperature, used in flame retardants |
[Ar] 3d¹⁰ 4s² 4p⁵ |
Used in flame retardants, photography |
HBr + Cl₂ → Br₂ + HCl |
Research on bromine-based water purification |
Wear protective gloves, avoid inhalation |
Toxic; can cause skin burns and lung irritation |
| Iodine (I) |
I-127 |
0.000049% (in Earth's crust) |
Trace |
-1 |
Essential for thyroid hormones |
[Kr] 4d¹⁰ 5s² 5p⁵ |
Used in medicine, disinfectants |
2I⁻ + Cl₂ → I₂ + 2Cl⁻ |
Research on iodine deficiency and thyroid health |
Use with care, can stain and irritate skin |
Deficiency causes goiter, excess is toxic |
| Astatine (At) |
At-210 |
Extremely rare |
Trace |
-1 |
Radioactive, used in cancer treatment |
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵ |
Potential use in targeted cancer therapies |
No stable chemical reactions observed |
Research on astatine in nuclear medicine |
Handle in radiation-protected environments |
Highly radioactive, poses serious health risks |
| Transition Metals |
Iron (Fe) |
Fe-56, Fe-57, Fe-58 |
5.6% (in Earth's crust) |
0.006% (in human body) |
+2, +3 |
Used in construction, machinery, blood transport (hemoglobin) |
[Ar] 3d⁶ 4s² |
Used in steelmaking, construction materials |
Fe + O₂ → Fe₂O₃ |
Research on iron-based catalysts for hydrogen production |
Wear protective gear, prevent rust exposure |
Iron deficiency leads to anemia, rust can contaminate water |
| Copper (Cu) |
Cu-63, Cu-65 |
0.0068% (in Earth's crust) |
0.0001% (in human body) |
+1, +2 |
Used in electrical wiring, coins, alloys |
[Ar] 3d¹⁰ 4s¹ |
Used in electrical wiring, jewelry |
Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag |
Research on copper nanomaterials for drug delivery |
Handle with care, prevent inhalation of copper dust |
Excess copper can cause liver damage, but necessary for enzyme functions |
| Zinc (Zn) |
Zn-64, Zn-66, Zn-68 |
0.007% (in Earth's crust) |
0.002% (in human body) |
+2 |
Essential for immune function and enzyme activity |
[Ar] 3d¹⁰ 4s² |
Used in galvanization, batteries |
Zn + 2HCl → ZnCl₂ + H₂ |
Research on zinc-based batteries |
Use gloves, avoid inhalation of zinc dust |
Essential in diet, but excess can cause toxicity |
| Nickel (Ni) |
Ni-58, Ni-60 |
0.009% (in Earth's crust) |
Trace |
+2 |
Corrosion-resistant, used in alloys |
[Ar] 3d⁸ 4s² |
Used in stainless steel, batteries |
Ni + Cl₂ → NiCl₂ |
Research on nickel in fuel cells |
Use in well-ventilated areas, can cause allergies |
Can cause skin irritation, toxic in high doses |
| Chromium (Cr) |
Cr-52, Cr-53 |
0.01% (in Earth's crust) |
Trace |
+2, +3, +6 |
Used in stainless steel, corrosion-resistant coatings |
[Ar] 3d⁵ 4s¹ |
Used in plating, pigments |
Cr₂O₃ + 2Al → 2Cr + Al₂O₃ |
Research on chromium toxicity and environmental effects |
Handle with caution, some compounds are toxic |
Hexavalent chromium is carcinogenic |
| Manganese (Mn) |
Mn-55 |
0.1% (in Earth's crust) |
Trace |
+2, +4, +7 |
Essential for metabolism, used in steelmaking |
[Ar] 3d⁵ 4s² |
Used in batteries, fertilizers |
MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O |
Research on manganese in battery technology |
Use protective gear, avoid inhaling dust |
Essential in small amounts, toxic in excess |
| Silver (Ag) |
Ag-107, Ag-109 |
0.000007% (in Earth's crust) |
Trace |
+1 |
Highly conductive, used in electronics and jewelry |
[Kr] 4d¹⁰ 5s¹ |
Used in electronics, mirrors, antimicrobial coatings |
AgNO₃ + Cu → Cu(NO₃)₂ + Ag |
Research on silver nanoparticles in medicine |
Wear gloves when handling silver compounds |
Non-toxic, but silver compounds can cause skin discoloration |
| Gold (Au) |
Au-197 |
0.0000004% (in Earth's crust) |
Trace |
+1, +3 |
Highly unreactive, used in electronics and jewelry |
[Xe] 4f¹⁴ 5d¹⁰ 6s¹ |
Used in jewelry, currency, medical implants |
2Au + 3Cl₂ → 2AuCl₃ |
Research on gold nanoparticles in medicine |
Safe to handle in pure form |
Biocompatible, used in medical treatments |
| Platinum (Pt) |
Pt-195, Pt-196 |
0.000005% (in Earth's crust) |
Trace |
+2, +4 |
Used in catalytic converters, resistant to corrosion |
[Xe] 4f¹⁴ 5d⁹ 6s¹ |
Used in catalysts, jewelry, cancer drugs |
PtCl₄ + 2H₂ → Pt + 4HCl |
Research on platinum-based cancer drugs |
Use gloves, some compounds are toxic |
Non-toxic in pure form, but some compounds are hazardous |
