How many distinct atoms make up atom bank or material science? How many atoms are in the universe and how do they change based on star, planet, comet, asteroid or dark matter?

In one line

The rule

Each element is a unique type of atom, defined by its number of protons. There are 118 known elements.

• The periodic table lists all known elements.
• Each element has a symbol (like H for hydrogen, Fe for iron).

Let's understand it simply

Imagine your kitchen has 118 different types of dal. Each dal is unique—some are big, some are small, some are red, some are black. But with just these 118 types, you can make thousands of different dishes.

Atoms are like those dal types. Each type is called an element (like hydrogen, oxygen, iron). When you mix them in different ways, you get all the things in the world: water, air, steel, even your body.

How it works

1. Atoms are the smallest building blocks of matter that keep their identity.
2. Each atom type is called an element. The number of protons in its nucleus decides which element it is.
3. The periodic table lists all 118 elements, from hydrogen (1 proton) to oganesson (118 protons).
4. In the universe, these atoms join to form molecules (like H₂O for water) and materials (like iron rods, wood, or plastic).
5. Different places in the universe have different mixtures of these atoms, depending on how stars and planets formed.

The story behind it

The idea of atoms started in ancient India and Greece, but scientists like John Dalton (England, 1800s) made it scientific. Dmitri Mendeleev (Russia, 1869) arranged the known elements into the periodic table, which helped predict new elements. Over time, scientists discovered more elements in labs and in stars. The last few, like oganesson, were made in special labs.

Where you see it in real life

• Iron rod in construction: Made mostly of iron atoms (Fe), sometimes mixed with carbon (C) to make steel.
• Water in your glass: Each drop has billions of H₂O molecules, made from hydrogen (H) and oxygen (O) atoms.
• Air you breathe: Mostly nitrogen (N) and oxygen (O) atoms, with a bit of argon (Ar) and carbon dioxide (CO₂).
• Gold jewellery: Pure gold is made of only gold atoms (Au).
• Pressure cooker whistle: The steam is water molecules, but the cooker itself is made of aluminium (Al) or stainless steel (iron, chromium, nickel).
• Stars like the Sun: Mostly hydrogen (H) and helium (He) atoms, fusing together to make energy.

Why it matters

• Material science: Knowing the types of atoms helps us make new materials (like plastics, alloys, medicines).
• Space science: Helps us understand what stars, planets, and comets are made of.
• Chemistry: All reactions depend on how atoms combine and change.
• Exams and careers: This is the base for chemistry, physics, and engineering.

Worked example

Let's estimate the number of atoms in a drop of water:

Given: 1 drop of water ≈ 0.05 mL
Step 1: 1 mL of water = 1 gram
Step 2: 0.05 mL = 0.05 grams
Step 3: 1 mole of water = 18 grams = 6.022 × 10²³ molecules
Step 4: 0.05 grams = (0.05/18) moles ≈ 0.00278 moles
Step 5: Number of molecules = 0.00278 × 6.022 × 10²³ ≈ 1.67 × 10²¹
Step 6: Each molecule has 3 atoms (2 H, 1 O)
Step 7: Total atoms = 1.67 × 10²¹ × 3 ≈ 5 × 10²¹ atoms

So, just one drop of water has about 5,000,000,000,000,000,000,000 atoms!

How many atoms in the universe?

Scientists estimate there are about 10⁸⁰ atoms in the observable universe. That's 1 followed by 80 zeros—a number so big it's impossible to imagine.

How atoms change in stars, planets, comets, asteroids, and dark matter

• Stars: Mostly hydrogen and helium. In their core, hydrogen atoms fuse to make helium and heavier elements.
• Planets: Mix of many elements. Earth has lots of iron, oxygen, silicon, magnesium, and others.
• Comets: Mostly ice (water, carbon dioxide) and dust (carbon, silicon, metals).
• Asteroids: Mostly rock and metal—iron, nickel, silicates.
• Dark matter: We don't know what it's made of. It may not be atoms at all, but something else entirely.

Common mistakes

• Thinking all atoms are the same: Each element's atoms are different because of their protons.
• Forgetting the periodic table has more than 100 elements: There are 118 known, but not all are found in nature.
• Believing dark matter is made of normal atoms: Scientists think it's something different, not regular atoms.
• Mixing up molecules and atoms: Atoms are single units; molecules are groups of atoms joined together.

Remember it

"Just 118 types of atoms make up everything you see, from your roti to the stars."