All About IB Sciences: Biology, Chemistry, Physics & Beyond

EduretiX
May 14
3 min read

If Group 3 is all about understanding people and society, Group 4 is where you dive into the natural world i.e atoms, cells, forces, ecosystems, and the very building blocks of life.

Whether you're a future engineer, doctor, researcher, or just someone who loves understanding how things work, Group 4 offers a suite of science subjects that train your mind to observe, hypothesize, experiment, and evaluate.

All about IB Group 4 IB Sciences: Biology, Chemistry, Physics & Beyond. HL and SL comparison and test structure.

Let’s break down the curriculum, assessment format, and unique features of IB Sciences, all in a student-friendly, conversational style.

What Subjects Fall Under Group 4?

Here’s your science menu:

Subject	What It Covers
Biology	Living organisms, ecosystems, cells, genetics, evolution
Chemistry	Structure of matter, chemical reactions, bonding, stoichiometry
Physics	Motion, energy, waves, electricity, fields, quantum theory
Environmental Systems & Societies (ESS)	A hybrid science + humanities course (counts as Group 3 or 4)
Computer Science	Software, logic, problem-solving, system fundamentals
Design Technology	Innovation, systems thinking, product development
Sports, Exercise and Health Science (SEHS)	Human anatomy, physiology, biomechanics, nutrition

Most students choose from Biology, Chemistry, or Physics. ESS is ideal for those who want a science with a broader environmental lens and less intense math.

What Do You Study?

Let’s use Biology/Chemistry/Physics as our core example, but most Group 4 subjects follow a common structure:

1. Core Topics (SL and HL)

Shared across all students in the subject. For example, in IB Physics:

Mechanics
Waves
Electricity and Magnetism
Thermal physics

2. Additional HL Topics

HL students study extra material in greater depth. For example, HL Physics adds:

Quantum and nuclear physics
Fields
Electromagnetic induction

3. Practical Work + Internal Assessment

Every science student conducts experiments, collects data, and draws conclusions, all while documenting in a lab notebook or digital journal.

Assessment Structure: How You're Graded

External Assessments (80%)

Paper	What It Tests	Duration (SL/HL)
Paper 1	Multiple choice on core topics	45 min / 1 hr
Paper 2	Short and long-answer questions (core + HL)	1 hr 15 / 2 hr 15
Paper 3	Data-based + optional topic questions	1 hr / 1 hr 15

Note: You are allowed a data booklet in most Group 4 exams.

Internal Assessment (IA) – 20%

You’ll conduct a personal scientific investigation and write a report (~6–12 pages). This can be a lab experiment, a field study, or even a simulation.

Examples:

“How does temperature affect enzyme activity?”
“Measuring the acceleration due to gravity using a pendulum”
“The effect of salt concentration on boiling point”

You design the method, analyze data, and discuss uncertainties. It’s your mini research project!

The Group 4 Project (Collaborative Science)

This is one of the coolest things about IB Science. Students from all Group 4 disciplines work together on a collaborative, interdisciplinary science project, typically based around a global theme (like sustainability, energy, or pollution).

It’s not graded but it builds teamwork, communication, and creativity, and many schools treat it like a mini science fair.

SL vs HL: What’s the Difference?

Feature	SL	HL
Hours of instruction	~150	~240
Depth of content	Core only	Core + extension topics
Math level	Moderate	More derivations & quantitative analysis
Career prep	General	Stronger foundation for STEM pathways

Choose HL if you're eyeing:

Medicine
Engineering
Research science
Data science
Environmental science

SL is perfect if you want a solid understanding but don’t plan on continuing science post-IB.

Real-Life Benefits & University Recognition

Science is a universal language and IB Science builds:

Lab competence and data analysis skills
Scientific literacy (a big deal in the age of AI, pandemics, and climate change)
Academic readiness for university-level science

Universities often give course credit for HL science, especially in the US. And in the UK, HL Biology and Chemistry are typically required for medicine or biomedical degrees.