GenEd: Lesson 27 Building Blocks of Life and Matter | Free LET Reviewer and Drill

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General Education

 Lesson 27

Building Blocks of Life and Matter

Atom to Organism 

[familiarize this]

In science, we often describe levels of organization from the smallest building blocks up to a whole living thing:

Image from Shutterstock

• Atom (A) – the smallest unit of an element.
• Molecule (mi) – two or more atoms bonded together (like H₂O).
• Organelle (O) – small structures inside cells (like mitochondria).
• Cell (C) – the basic unit of life.
• Tissue (T) – a group of similar cells working together.
• Organ (O) – a structure made of different tissues (like the heart).
• System (S) – a group of organs working together (like the digestive system).
• Organism (O) – a complete living individual (a person, a plant, an animal).

Just remember this as “AMOCTOSO”

 

Atom, Matter, and Non‑Matter

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An atom is the basic building block of matter. Every atom has three main parts:

• Protons (p⁺) means positively charged, in the nucleus.
• Neutrons (n⁰) means no charge, in the nucleus.
• Electrons (e⁻) means negatively charged, move around the nucleus.

You can remember this as PEN: Proton, Electron, Neutron.

Non‑matter is anything that does not occupy space and does not have mass, such as light, sound, and ideas. Matter, on the other hand, is anything that occupies space (has volume) and has mass. All solids, liquids, and gases are matter.

 

Matter

Image from Science Notes

All matter can be placed into two main groups: pure substances and mixtures.

• Pure substances
• Have only one kind of particle (all the same atoms or all the same molecules).
• Have fixed composition and properties (do not vary from sample to sample).
• Two types: elements and compounds.

• Mixtures
• Have two or more different substances physically combined.
• Components can often be separated by physical means (filtering, evaporation, etc.).
• Two main types: homogeneous and heterogeneous mixtures.

Image from courses lumen learning

• Matter
• Pure Substances
• Elements (metals, non‑metals, metalloids)
• Compounds - substances made by (bonding) two or more different elements together like "hydrogen" + "oxygen" = water

• Mixtures
• Homogeneous - mix that looks exactly the same from top to bottom, like a glass of water with a salt in it, you cannot notice the salt unless you inspect it thoroughly.
• Heterogeneous - mix where you can easily see the different, like a bowl of cereal and milk. You can literally see cereal and milk inside the bowl.

Elements and Their Classes

Elements are those pure substances which contain only one type of atoms. Elements can neither be divided into smaller particles nor be combined to form another type of substance through chemical reactions. Some examples of elements are oxygen (O₂), hydrogen (H₂), sodium (Na), iodine (I₂), and gold (Au). The total number of all elements found till now is 118, and Oganesson (Og) is the 118th element.Elements are grouped into:

Image from NemoQuiz

Metals

• Usually solid at room temperature (except mercury and also gallium, which can be liquid around room temperature).
• Good conductors of heat and electricity.
• Often shiny, malleable (can be hammered into sheets), and ductile (can be drawn into wires).
• Examples: copper (Cu), iron (Fe), aluminum (Al).

Non‑metals

• Generally poor conductors of heat and electricity.
• Can be gases, liquids, or brittle solids.
• Examples: oxygen (O₂), carbon (C), bromine (Br₂), sulfur (S).

Metalloids (semi‑metals)

• Have properties in between metals and non‑metals.
• Often semiconductors (used in electronics).
• Examples: silicon (Si), germanium (Ge).

 

Compounds and Chemical Bonding

Image from Britannica

A compound is a pure substance made from the chemical combination of two or more different types of atoms in a fixed ratio. Compounds can be broken down into simpler substances by chemical means (but not by physical methods like filtering).

Examples:

• Water (H₂O) – two hydrogen atoms and one oxygen atom.
• Carbon dioxide (CO₂) – one carbon and two oxygen atoms.
• Table sugar (C₁₂H₂₂O₁₁).
• Table salt (NaCl) – sodium and chlorine.

Example: Alcohols are a class of organic compounds that contain a hydroxyl (–OH) group attached to a carbon chain (an alkyl group). Ethanol, the alcohol found in drinks and some sanitizers.

Hard to understand? Much simpler explanation.

Think of a compound like a cake recipe. You take different ingredients (atoms), mix them in a fixed amount, and bake them together. Once baked, you can't just "filter" the flour back out; you’d need a complex chemical process to separate them. 

For instance in a fixed ratio it’s always the same "recipe." Water is always two hydrogens and one oxygen. If you change that ratio, it’s not water anymore.

Now in chemical bond the atoms are "glued" together. You can't separate salt by just using a sieve or a magnet; you have to use chemistry to break those bonds. When atoms join to make a compound, they lose their old traits. For example, Chlorine is a deadly gas and Sodium is a reactive metal, but together they make Table Salt, which you use in cooking and eating everyday. 

In my earlier example which is “alcohols” are just a family of these recipes. They all have one thing in common: called a hydroxyl group (one oxygen and one hydrogen bonded together) stuck onto a chain of carbon atoms

Compounds are held together by chemical bonds. Two important types are:

Covalent bonds

• Form when two or more non‑metal atoms share electrons.
• Examples:
• H₂O (water) – hydrogen and oxygen (both non‑metals).
• CH₄ (methane).
• CO₂ (carbon dioxide).

Ionic bonds

• Form between metals and non‑metals, where electrons are transferred from metal to non‑metal.
• Examples:
• NaCl (sodium chloride).
• NaF (sodium fluoride).

 

Mixtures

Image from BYJU's

A mixture is a type of matter made of two or more different substances that are combined without chemical bonding. Each substance keeps its own properties, and they can usually be separated by physical methods (like filtering, dissolving, or evaporating).

Homogeneous mixture

A homogeneous mixture has a single phase and looks uniform throughout. You cannot see different parts with the naked eye.

• Examples:
• Water + sugar = sugar solution.
• Water + salt = brine (salt solution).

Heterogeneous mixture

A heterogeneous mixture has components that are visibly different. You can see separate parts.

• Examples:
• Salad (you see lettuce, tomato, etc.).
• Gravel.
• Macaroni soup.
• Cake with visible chunks.

Within heterogeneous mixtures, we often distinguish:

Image from PSIBERG

Colloid

• Contains tiny particles that do not settle upon standing.
• Looks uniform, but the particles are bigger than in a true solution.
• Examples: milk, clouds, fog.

Suspension

• Contains larger particles that eventually settle out if left undisturbed.
• Examples: chocolate milk, orange juice with pulp, some liquid medicines (like vitamin suspensions).

Building Blocks of Life and Matter Quiz

“I will pass the board exam. I will be a Licensed Professional Teacher. I believe in myself and my hard work. Write your name in the comments with LPT beside it to manifest”

Example: Juan Cruz, LPT

If you don’t claim it, you lose it
With God’s grace, you’ll surely pass the upcoming board exam! 🙏

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